The invention provides a mechanical leg and a robot. The mechanical leg comprises a first swing arm assembly, a second swing arm assembly and a driving assembly, and the first swing arm assembly and the second swing arm assembly are mounted on the driving assembly side by side; the first swing arm assembly comprises a first transmission arm, a first supporting arm and a first motor, one end of thefirst transmission arm is connected with the first motor, and the other end of the first transmission arm and one end of the first supporting arm are hinged; the second swing arm assembly comprises asecond transmission arm, a second supporting arm and a second motor, one end of the second transmission arm is connected with the second motor, and the other end of the second transmission arm and one end of the second supporting arm are hinged; and the other end of the first supporting arm and the other end of the second supporting arm are hinged. According to the mechanical leg and the robot, by adopting the first swing arm assembly and the second swing arm assembly which are mounted side by side, the load and the inertia of the first motor and the second motor are lowered, the loading capability of the mechanical leg is improved conveniently, the strength and rigidity of the mechanical leg are improved, and the response speed of the mechanical leg is increased.