The invention discloses an embryo-reduction device, which comprises a puncture needle body and a signal-radiation plate, wherein the puncture needle body is in a hollow structure; the point of the puncture needle body is provided with a motor; one end of the motor is fixed with an output shaft; the tip of the output shaft is provided with rotary vanes; the other end of the motor is fixedly provided with a screw rod which is in screw match with a screw rod pusher; the screw rod pusher is fixed on the inner wall of the puncture needle body through a bracket; the screw rod pusher is provided with an expansion signal receiver; the motor is provided with a switch signal receiver; the signal-radiation plate is provided with a switch signal radiator matched with the switch signal receiver and anexpansion signal radiator matched with the expansion signal receiver. The invention is suitable for the embryo pregnant for more than 8 weeks, does not need medicine injection, and has small operation range, short operation time and small residual slough.