The invention provides a corner self-servo passive and supple hydraulic robot joint. According to the technical scheme of the corner self-servo passive and supple hydraulic robot joint, a valve body (14) is concentrically installed in a cylindrical cavity (32) of a cylinder body; the left end and the right end of the valve body (14) are concentrically provided with two deep groove ball bearings (5); a driving bevel gear (13) is concentrically installed on the shaft shoulder of an output shaft at the right end of the valve body (14); a driven shaft (12) is installed on a right end cover (7); a driven bevel gear (8) is concentrically installed on the driven shaft (12); two connecting rods (9) are fixedly and symmetrically installed at the two ends of the driven shaft (12) through screws; and a driven arm (10) is installed between the other ends of the two connecting rods (9). The corner self-servo passive and supple hydraulic robot joint has the beneficial effects that a fixing stop block can be fixed easily and assembled easily, the output torque of the joint is large, the force borne by the valve body is in balance, displacement is not prone to occurrence, the dynamic characteristic is good, the joint flexibility is good, the response speed is high, and the control precision is high.