The invention belongs to the technical field of mode recognition, and particularly relates to a human body posture recognition system based on millimeter-wave radar. The system comprises a millimeterwave radar subsystem, a data processing and tracking positioning subsystem and an artificial intelligence classification subsystem. The millimeter wave radar subsystem transmits linear frequency modulation continuous wave signals to a detection range, collects radar echo data reflected by a human body, and outputs intermediate frequency original data after frequency mixing, filtering and analog-to-digital conversion sampling. The data processing and tracking positioning subsystem extracts various characteristics, including distance, speed, acceleration, orientation characteristics and the like, capable of representing the posture of the human body from the original data, and tracks and positions the position of the human body in real time. The artificial intelligence classification subsystem filters, classifies and judges the feature information, and determines the posture of the human body by integrating classification and judgment results. The system aims at human body posture recognition and state monitoring in real life, and can be suitable for scenes such as families, offices, factory workshops, hospital wards and nursing homes.