The invention provides a system and method for detecting the sitting postures of the human body on the basis of video information and piezoelectric information. The system comprises a pressure sensor,a skeleton identification module, an STM32 single chip microcomputer and a display module. The method comprises the steps of separately acquiring sitting pressure information of the back and buttocksof the human body through a back piezoelectric sensor array and a bottom piezoelectric sensor array; acquiring human body skeleton image information through a Kinect depth camera to acquire human body skeleton information; judging a first human sitting posture type according to the sitting pressure information; judging a second human sitting posture type according to the skeleton information; ifthe first human body sitting posture type and the second human body sitting posture type are the same, obtaining a final human body sitting posture type, counting the holding time of the final human body sitting posture type, and if the holding time exceeds a preset time corresponding to the final human body sitting posture type, sending a health prompt to a user. The method has the advantages that the precision of identifying the human body sitting posture types is improved; the detection method is simple and high in practicability.