The invention relates to a numerically controlled three-degree-of-freedom coordinated control electric drive system for a large-sized mining excavator. The electric drive system comprises a man-machine monitoring device, a PLC (programmable logic controller) with a converting drive controller, a converting drive device, a protective device and a cab control device which are sequentially connectedtogether. The numerically controlled three-degree-of-freedom coordinated control electric drive system has the following advantages: 1. reasonable design, simple structure, smaller noise and completepracticability; 2. adequate adaptability to characteristics of the excavator such as frequent load change, rotation blockage, variable inertia, great vibration and shock, great environmental temperature difference and the like; 3. accurate control, strong anti-interference performance, fast dynamic response, high power factor and less harmonic pollution on a power grid; and 4. small shock vibration on transmission machinery, strong load adaptability, good robustness, low maintenance cost and high reliability.