Disclosed is a hydraulically driven joint for a robot, which comprises a screw-in cartridge rotary direct-drive electro-hydraulic servo valve and a vane oscillating hydraulic cylinder special for a robot motion joint, the screw-in cartridge rotary direct drive electro-hydraulic servo valve is hereinafter referred to as a hydraulic cartridge rotary direct-drive valve and the vane oscillating hydraulic cylinder special for the robot motion joint is hereinafter referred to as a vane oscillating cylinder, a valve body installation cavity is prefabricated at one end of a center of a center rotating shaft of the vane oscillating cylinder, a shape of the valve body installation cavity is manufactured according to a shape of a plug-in portion of the hydraulic cartridge rotary direct-drive valve, and the hydraulic cartridge rotary direct-drive valve is plugged into the valve body installation cavity.