Fluorescence endoscope, which enables simultaneous visible light imaging and near-infrared fluorescence molecular imaging, is a result of advanced endoscopic theories and cutting-edge technologies. This instrument holds great potential to become an essential visual monitoring system in future targeted surgeries. The optical performance of the notch filter within the fluorescence endoscope plays a pivotal role in determining the clarity and precision of identifying fluorescence images of lesions, thereby influencing the endoscope's efficacy in supporting diagnostics and advancing precision medicine in clinical practice. Consequently, research into critical technologies related to notch filter for fluorescence endoscopy and the development of high-performance filter products demonstrate significant clinical application prospects and scientific significance. By aligning the operational principles of the fluorescence endoscope with the spectral profiles of corresponding fluorescent reagents, we can define the technical specifications for notch filter. Based on the theory of optical film, we have designed a notch filter utilizing K9 substrates, characterized by the deposition of notch coating and anti-reflective coating on both sides. The design of the notch coating was achieved by optimizing the matching of high and low refractive index coefficients, which is based on an in-depth comparison of the merits and drawbacks of Rugate filters, Rugate filters with step-change refractive index, methods for matching high and low refractive index coefficients, and other notch structures. Moreover, we employed Essential Macleod software in conjunction with various optimization synthesis methods to achieve high passband transmission, minimal ripple, excellent blocking property for the excitation light source, as well as a steep transition from the excitation spectrum to the emission spectrum. This approach ultimately enables efficient suppression of the excitation light and efficient capture of fluorescence signals, playing a crucial role in accurately identifying lesions. To ensure precise control, a plasma reaction magnetron sputtering coating device is selected after simulating and analyzing the standard deviation of film thickness. The coating process involves ultrasonic cleaning and drying of substrates to maintain cleanliness, followed by heating the vacuum chamber to 200 ℃ and maintaining a constant temperature for 30 minutes to remove gas. This is followed by ion bombardment of substrates for 120 seconds to activate the surface. The deposition rates for Nb₂O₅ and SiO₂ are both set at approximately 0.5 nm/s for coating applications. To ensure complete oxidation of the sputtered film, we employ an oxygen partial pressure sensor (λ-sensor) to monitor the deposition process and measure oxygen content. The system is equipped with an Optical Monitoring System (OMS) film thickness control system that uses a combination of Backward, Offset, and Forward algorithms to accurately calculate and correct the stop position of film thickness. This approach enables precise control over sensitive layer thickness in complex film systems, thereby reducing the impact of errors on the overall spectrum. By carefully selecting substrates with wavefront aberration control and implementing stringent coating process control methods, we ensure that the wavefront aberration remains below λ/4 @632.8 nm, effectively minimizing optical system aberrations. After two rounds of meticulous process optimization, the filter's average transmittance within the passband exceeds 97%, while maintaining an exceptional blocking capability of OD6 and a wavefront aberration below λ/4 @ 632.8 nm, meeting the demands for precision applications in medical and minimally invasive surgery.