Recently, photon counting imaging technology has become a research frontier in the field of LiDAR technology owing to its high sensitivity, high time resolution, and high photon efficiency. Efficient image reconstruction algorithms can improve the quality of reconstructed images at lower costs based on hardware systems or break through the bottleneck of solely relying on hardware technology, which has become a trending issue in the field of photon counting imaging technology. Aiming at the existing photon counting imaging algorithm, this study systematically sorts out the principles and characteristics of photon counting imaging technology, conducts in-depth investigations and discussions on several common issues, and considers and looks forward to the future development trend of this field.