In recent years, mid-infrared (wavelength range of 2–20 μm) integrated photonics has received a lot of attention for its potential applications, including absorption spectroscopy, thermal imaging, and free-space communication. The mid-infrared, which includes several atmospheric transparency windows, has an inherent advantage for sensing applications. The mid-infrared photonic devices also benefit from the mature technologies developed in the near-infrared for device design, test, and fabrication. In addition, integrated photonic sensors have demonstrated comparable sensitivity to their bulk counterparts, while featuring low power consumption, low cost, compact structure, and easy integration with other devices. Therefore, the mid-infrared integrated photonic sensors will play an important role in industrial detection, scientific research, medical diagnosis, military security, life, and other fields in the future. Here, Recent advances in the mid-infrared integrated photonic sensors have been reviewed. Three major components, sensing unit, spectrometer, and detector were discussed. An outlook for its future development was also proposed.