The invention discloses an automatic pad printing machine. The automatic pad printing machine comprises a transfer platform and a printing mechanism. An extending-retracting roller wheel, a rotating motor and a horizontal adjusting rod are arranged at the two ends of cleaning adhesive tape of the printing mechanism. The extending-retracting roller wheel is driven to rotate through the rotating motor. The transfer platform comprises a horizontal movement mechanism, a movable motor, a movable platform and a workpiece fixture. The workpiece fixture is driven to horizontally move through the horizontal movement mechanism. The movable motor drives the horizontal movement mechanism to move below a pad printing rubber head. The horizontal movement mechanism comprises a rotating motor and a multifunctional rotating disc, and the multifunctional rotating disc is driven to rotate through the rotating motor so that the direction can be adjusted. The automatic pad printing machine is divided into the transfer platform and the printing mechanism; the transfer platform can rotate in a plurality of directions so as to drive a workpiece, and flexible printing is achieved; and the printing mechanism uses the horizontal adjusting rod to adjust the position of the cleaning adhesive tape, so that the cleaning adhesive tape corresponds to the position of the above pad printing rubber head, and direct cleaning is convenient.