The invention discloses a material overturning mechanism on a conveying belt and solves the problems of inconvenient operation and high labor intensity of workers during manual material overturning atpresent. The material overturning mechanism comprises a conveying support and a conveying belt assembled on the conveying support rotationally. The material overturning mechanism is characterized inthat a supporting frame is arranged on the conveying support; two air cylinders are symmetrically assembled at the top end of the supporting frame; a motor support is fixedly connected between rod parts of piston rods of the two air cylinders; a motor is assembled on the motor support; connecting seats are arranged at the ends of the piston rods of the two air cylinders; rotating shafts are rotationally connected onto the connecting seats; overturning shifting forks are arranged at the ends of the rotating shafts; and the rotating shafts are driven by the motor through a transmission piece torotate in a reciprocating manner, so that the overturning shifting forks are driven to shift materials to be overturned. The material overturning mechanism is simple to operate and convenient to use,and the labor intensity of the workers is low.