A motor-driven gate comprises a motor, a big gear wheel, a pinion, a lead screw, a nut block, a gate board, a frame and a plurality of big idler wheels; a sluice gate is arranged in the frame; the gate board is arranged in the frame and can move horizontally along the length direction of the frame to open and seal the sluice gate; the big idler wheels are arranged on the motion path of the frame to support the gate board; the motor is arranged on the frame, the pinion is arranged on a rotor of the motor; and the gate board is connected with the lead screw by the nut block, the lead screw is connected with the big gear wheel, and the big gear wheel is meshed with the pinion. The motor-driven gate has the advantages that since gear drive and screw pair drive are combined and an overtravel-limit switch is used to control the motor to turn forwards and backwards to realize the opening and closing of the gate, the motor-driven gate is simple, reasonable and reliable, is easy to operate, has high transmission efficiency and low failure rate, and can realize automatic control.