Large sheet turnover machine

The utility model discloses a large sheet turnover machine which comprises a machine frame body, a first driving motor, a driving shaft, a belt conveying mechanism, a second driving motor, a turnover frame, a left side plate, a right side plate, a second bearing seat, an air cylinder, a pressing plate and a cylinder seat. The left side plate and the right side plate are fixedly installed on the left side and the right side of the overturning frame respectively, the driving shaft is rotatably installed at the left end of the machine frame body through a first bearing and a first ball bearing seat, and an output shaft of the first driving motor is in transmission connection with the driving shaft through a coupler. The two second driving motors drive the upper belt conveying mechanism and the lower belt conveying mechanism to rotate in the forward direction and rotate in the reverse direction to guide out the large plate, the large plate is borne and guided through the discharging guide plate, and then the larg