The invention discloses a gesture-interaction-supported projection method. A projection system is in the working state, a whole projection screen can be captured by adjusting the visual angle of a camera, the projection screen is shot continuously through a camera according to preset time intervals to collect images, binarization processing is executed, differential operation is conducted on the collected images through a difference image method, and screen change difference images containing projection of a moving hand portion are obtained; according to the obtained continuous difference images, the target region density distribution feature is computed, gesture identification and gesture track detection are conducted, a handshape type or a gesture command type is judged, and the projection content of a projector is controlled and adjusted. By means of the method, human body input actions can be recognized, the projection figure content is adjusted according to different movement trend of gestures, good human-computer interaction is achieved, and the method has good application prospects.