The invention discloses a robot leg, which aims at solving the problems that the existing heavy-loaded large-scale six-foot robot generally uses a hydraulic cylinder for driving, and the obstacle passing capability of the six-foot robot is limited. The robot leg comprises a blade type swinging hydraulic motor, a robot calf, a robot thigh and a robot base section, wherein the blade type swinging hydraulic rotor comprises a motor casing, a first hydraulic oil inlet and outlet opening, a second hydraulic oil inlet and outlet opening, a flange installing hole and two output shafts. The leg structure is subjected to fire-new design; the bearing and obstacle passing requirements of the heavy-loading large-scale six-foot robot can be effectively met. In the robot leg, on the basis of the robot leg structure improvement, the blade type swinging hydraulic motor is introduced for leg joint driving, so that the defects of small rotating angle and low obstacle passing capability of the conventional hydraulic cylinder driving heavy-loading large-scale six-foot robot can be effectively overcome. The design is ingenious; the design is reasonable; the structure is simple; the use is convenient; high application values and good application prospects are realized.