Photoacoustic Spectroscopy (PAS) technology is an essential technique for detecting gas concentrations due to its rapid response time, strong anti-interference capabilities, high sensitivity, and excellent resolution. These features have made PAS broadly applicable across fields such as atmospheric monitoring, power diagnostics, healthcare, and environmental analysis. In PAS, a modulated laser beam targets gas molecules contained within a sealed photoacoustic cell. Upon absorbing the laser energy, these molecules transition to a high-energy state and subsequently release the absorbed energy through non-radiative decay, returning to their initial state. This process converts the absorbed energy into kinetic energy, causing the periodic heating of the sample and surrounding medium, synchronized with the laser's modulation frequency. This periodic heating induces pressure fluctuations, which generate an acoustic signal. A micro-acoustic sensor then converts this acoustic signal into an electrical signal, enabling the precise measurement of gas concentration through data acquisition and processing. The photoacoustic cell, as the core component of the PAS detection system, serves as the medium for the sample's photoacoustic effect and is crucial for amplifying the signal while maintaining immunity to external interference. The cell’s shape and configuration significantly impact the system's sensitivity and signal-to-noise ratio, underscoring the importance of optimized cell design for advancing both theoretical understanding and practical applications. To enhance photoacoustic cell performance, various structural optimizations have been explored, including resonant cylindrical photoacoustic cells, H-type and T-type cells, ellipsoidal resonant cavities, and hyperbolic busbars. Conventional photoacoustic cell design often relies on finite element analysis to determine optimal dimensions by controlling variables and scanning parameters. However, for complex geometries, this process is time-intensive, creating demand for streamlined methods that can effectively optimize the acoustic and flow characteristics of photoacoustic cells, even with intricate designs. This study proposes a novel parameter optimization approach specifically for irregularly shaped photoacoustic cells, integrating the Design of Experiments (DOE) methodology with the Non-dominated Sorting Genetic Algorithm (NSGA-II). Using this integrated approach, a synaptic photoacoustic cell was designed, and its performance was validated against that of conventional cylindrical photoacoustic cells. The synaptic photoacoustic cell includes several structural components: a resonant cavity, two buffer chambers (both arc-shaped and cylindrical), an acoustic sensor, one air inlet, one air outlet, and two window panes. Key design parameters include the length and radius of the resonant cavity, the radius of the buffer chamber, and the respective lengths of the arc-shaped and cylindrical buffer chambers. The arc-shaped buffer chamber connects tangentially to the resonant cavity, thereby optimizing sound and flow characteristics within the photoacoustic cell. Compared with conventional cylindrical photoacoustic cells, the synaptic photoacoustic cell design offers distinct advantages, including enhanced acoustic signal strength, sound energy efficiency, and reduced noise caused by vortex-induced gas flow disturbances. Additionally, the smaller cavity volume of the synaptic photoacoustic cell reduces sample fill time, enabling faster response rates and a more efficient analysis process. A modal analysis of the first eight acoustic modes reveals increasing complexity with higher modal orders, indicating a sophisticated internal sound distribution. In the second-order mode, sound pressure is maximized in the center of the resonant cavity, where the acoustic sensor can detect signals with enhanced effectiveness. Meanwhile, minimal sound pressure in the buffer chamber makes this area optimal for placing inlets and outlets, as it minimizes external interference with the cell’s performance. This study applies DOE to assess photoacoustic cell parameters with high efficiency, reducing the number of necessary trials while enabling comprehensive evaluation of variable interactions. Specifically, the Box-Behnken response surface method was applied in 41 experiments to analyze sound pressure and quality factor. The response surface proxy model generated from the experimental results reveals nonlinear relationships among the parameters, necessitating a balanced optimization approach. The NSGA-II algorithm, configured with 500 generations and a population size of 50, produced a Pareto-optimal solution set for sound pressure and quality factor. From this solution set, an optimal design was identified, yielding improvements in both parameters over traditional cylindrical photoacoustic cells. The optimized dimensions for the synaptic photoacoustic cell include a resonant cavity length of 30.03 mm, a radius of 3.42 mm, a buffer chamber radius of 29.99 mm, an arc-shaped buffer chamber length of 50 mm, a cylindrical buffer chamber length of 20 mm, and an arc radius of 56.68 mm. Using COMSOL software, this study further simulates and compares the acoustic and flow field characteristics of the optimized synaptic photoacoustic cell against those of traditional cylindrical photoacoustic cells. Results demonstrate a 41.8% increase in sound pressure and a 16.03% improvement in the quality factor. Additionally, the synaptic photoacoustic cell reduces vortex flow area by 62.75% and achieves a 66.27% reduction in volume, enhancing overall system efficiency. In practical NO? gas detection experiments, the synaptic photoacoustic cell exhibits a resonant frequency of 2 553 Hz, a quality factor of approximately 70.16, a rising edge response time of 32 seconds, and a falling edge response time of 28 seconds. Stability tests conducted over five hours indicate a mean signal variance of (3.851±0.023) V, underscoring the synaptic photoacoustic cell's robust acoustic focusing ability, rapid response, and compact structural design. In summary, the synaptic photoacoustic cell developed in this study demonstrates significant improvements in both acoustic and flow field performance. These enhancements provide a substantial upgrade over traditional photoacoustic cells and offer valuable insights for future PAS detection system optimization, enabling more efficient and precise gas detection across various applications.