The invention discloses a die changing trolley of a press machine in the field of press machines. The die changing trolley comprises a trolley body; the bottom of the trolley body is provided with wheels, the trolley body is provided with a driving mechanism, a pair of die carrier guide rails and a die carrier pushing-pulling mechanism, the die carrier pushing-pulling mechanism comprises a pushing-pulling motor, the output end of the pushing-pulling motor is provided with a belt pulley I, and the belt pulley I is connected with a belt pulley II in a driving way through a belt to which a sliding pothook is connected; the lower part of a die carrier is provided with double rows of die carrier rollers, the trolley body is provided with a die carrier limiting mechanism comprising a base plate, the base plate is provided with a slide wheel axle which is rotatably connected with a side wheel, and the upper end of the side wheel axle is provided with a pressing plate; and the trolley body is provided with a die carrier lifting mechanism in parallel, the die carrier lifting mechanism comprises a roller carrier controlled by a hydraulic cylinder to lift, horizontal rollers are horizontally arranged on the roller carrier, and roller shafts of the horizontal rollers are parallel to the die carrier guide rails. By using the die changing trolley, the die carrier of the press machine can be rapidly changed, the die changing time can be shortened, and the die changing efficiency can be increased.