Bound states in the continuum (BIC) lasers have garnered significant attention in the field of photonics due to their ultra-high quality factor (Q-factor) and low-threshold lasing characteristics. The concept of BIC originally emerged from quantum mechanics and was later introduced into optical systems, where it has been extensively studied in photonic crystals, metasurfaces, and microcavity systems. The fundamental principle of BIC lasers lies in the precise engineering of optical structures to suppress radiation loss for specific modes, thereby creating highly localized high-Q states. This mechanism breaks the limitations of traditional optical cavities and enables the realization of ultra-high Q values and highly efficient laser emission. By leveraging symmetry protection, parametric tuning, or topological design, BIC lasers can achieve high-Q modes, offering a new pathway for the development of low-loss, high-coherence light sources. BIC is a unique optical phenomenon in which certain optical modes, despite being located in the radiation continuum, remain bound and do not couple with external radiation. This phenomenon is caused by specific symmetries and designs of structures, which, under certain conditions, can confine light in a specific region without radiation leakage. The characteristics of BIC modes include low loss, high Q factor, and strong localization. They are often applied to enhance the performance of optical devices, especially in the design and optimization of lasers. The introduction of BIC has provided new breakthroughs in improving efficiency and optimizing output. Firstly, BIC plays a crucial role in optimizing the high Q factor of lasers. The Q factor represents the quality factor of the system, measuring the light storage capacity within the cavity and the efficiency of the interaction between light and matter. Traditional laser Q factor optimization typically depends on the cavity structure and the choice of gain media. However, the introduction of BIC modes offers a more efficient path for this optimization. BIC modes, with their low loss and strong localization, allow light to remain within the cavity for extended periods, significantly improving the Q factor of the laser. Moreover, the unique properties of BIC enable mode selectivity across different wavelength ranges, further enhancing the stability and efficiency of the laser. Therefore, BIC not only improves the Q factor of the laser but also shows great potential in miniaturized lasers and high-precision laser systems. In terms of optimizing laser output, BIC also plays a key role, especially in optimizing single-mode output. Single-mode output is one of the core performance indicators of a laser, ensuring that the laser outputs stable and consistent modes. However, traditional lasers often face the issue of multi-mode output, which leads to instability and reduced precision. By incorporating BIC modes, lasers can avoid multi-mode competition and achieve single-mode output. BIC modes have strong mode selectivity, allowing precise control over the resonant conditions of the laser and limiting the output to specific resonant modes, thus preventing interference from traditional multi-mode outputs. Additionally, the localization characteristics of BIC ensure that the laser can operate stably without external disturbances, greatly enhancing the stability and efficiency of single-mode output. With the rapid advancement of intelligent manufacturing and autonomous driving, the demand for high-performance lasers has increased significantly. BIC lasers, as an emerging field, have shown great potential due to their ultra-high Q factors and enhanced mode control. Key optimizations include merging multiple BICs to form new modes, utilizing photonic bandgap effects to enhance localization, and introducing phase-change materials for improved tunability. Expanding high Q regions in momentum space also strengthens robustness against external variables and fabrication imperfections. However, challenges remain, such as balancing high Q factors with increased threshold currents, reducing complex manufacturing costs, and mitigating nonlinear effects and thermal instabilities. Despite these obstacles, advancements in optical materials and nanofabrication technologies provide promising prospects. BIC lasers are expected to play a crucial role in high-performance laser applications, including optical sensing, quantum information, and optical manipulation, driving the future of photonic technology.