The background of imaging photoplethysmography (IPPG) is briefly presented from biological and physical perspectives. Taking the optimization of the IPPG signal as the starting point, the effects of external factors and the original signal extraction process are introduced respectively. External factors such as the green light source in the ambient light source have the highest signal-noise ratio (SNR), with No significant effect on light intensity. The lighter the skin color of the human body, the higher the SNR, with gender having no effect. The extraction of the original signal such as the region of interest (ROI) region selects the face T -zone with the highest SNR. The original signals are extracted by the Cg channel in the YCbCr, which is better than other color spaces. Face detection algorithms and tracking algorithms are intended to solve the problem of signal quality degradation caused by small movements, background changes, and missing angles in face video shooting, including the degradation of video quality during transmission. physiological parameters are measured by formula conversion and fitting. At present, there is still a lot of room for the development of this detection technology, and domestic and foreign research should be towards eliminating motion artifacts. Efforts have been made to improve the detection effect in the absence of local information, develop new applications of IPPG detection technology, better process compressed data, and combine daily portable devices with the direction of use.