Belt-driven three-joint five-degree-of-freedom mechanical arm

The invention relates to a belt-driven three-joint five-degree-of-freedom mechanical arm which is used for solving the problems that an existing mechanical arm is large in rotational inertia, low in control precision and low in load. The mechanical arm specifically comprises a mechanical claw assembly, a wrist joint and small arm assembly, an elbow joint and large arm assembly and a base joint assembly. The angle of the mechanical claw assembly relative to the wrist joint and small arm assembly is changed through belt transmission drive by a wrist joint motor assembly which is installed on an elbow joint in a downward moving mode, the angle of the wrist joint and small arm assembly relative to the elbow joint and large arm assembly is changed through belt transmission drive by an elbow joint motor which is installed on a base joint in a downward moving mode, and the mechanical arm is used for reducing rotational inertia generated when a mechanical arm assembly moves. The elbow joint motor is integrated at the