Abstract: Disclosed is an automatic injection syringe. A telescopic push rod driven by a motor is installed in the syringe, and the medicine injection tube is detachably placed in the syringe; the telescopic push rod comprises a rear rod, a fixed disc, a lead screw assembly, a sliding disc and a front rod, one end of the rear rod is installed on an inner cavity rear end cover of the syringe, the other end of the rear rod is fixedly connected with the fixed disc, the transmission end of the lead screw assembly is installed on the fixed disc, the sliding disc is fixed to nuts of the lead screw assembly, one end of the front rod is fixed to the sliding disc, and the other end of the front rod is inserted into a piston piece at the top of the medicine injection tube in a matched mode.