The infrared spectral region encompasses a wealth of information regarding molecular vibrations and thermal radiation, making it crucial for applications in detection, sensing, and thermal management. As infrared devices evolve toward higher sensitivity, miniaturization, and integration, traditional device architectures have begun to limit performance improvements. Bound states in the continuum (BICs) and their excitable counterparts, quasi-BICs, offer an effective pathway to achieving high quality factors and strong optical field confinement. Through deliberate symmetry breaking or structural perturbations, ideal BICs can be converted into quasi-BIC resonances with finite radiative leakage, enabling narrow-linewidth spectral responses and efficient free-space coupling. This paper provides a comprehensive review of the physical mechanisms and typical implementation approaches of quasi-BICs. It summarizes research progress in areas such as infrared absorption enhancement, infrared sensing, thermal radiation manipulation, and active infrared modulation, while also discussing extended applications in infrared lasers, up-conversion imaging, and strong light-matter coupling. Finally, the paper analyzes current challenges in quasi-BIC-driven infrared devices concerning loss management, structural robustness, and on-chip integration, and offers an outlook on future development trends.