Provided is an electromechanical-linkage hydraulic control gate valve actuator. The actuator includes a hand-operated speed-increasing gearbox assembly and a bidirectional throttle valve. In the present invention, a motor is driven to rotate through the hand-operated speed-increasing gearbox and thus a hydraulic system is driven to finally open and close a gate valve. An opening and closing speeds of the gate valve can be regulated and controlled through the bidirectional throttle valve. The present invention drives the motor through the hand-operated speed-increasing gearbox under emergency conditions such as repair and power failure, thereby controlling to open and close the gate valve. Meanwhile, a hydraulic system respectively regulates the speeds of two states of opening and closing through a bidirectional throttling technique, so as to effectively eliminate a water hammer phenomenon. The present invention has simple structure, light weight and modular installation, and enhances safety and reliability.