A completely new excavator driving mode is proposed，while the whole hydraulic system within the original excavator is being discarded. To get the work done, the machine is driven by motors directly. PC200-8 is redesigned and some selection is made after analysis and calculation. The driving force is generated by 7 servo motors while each electric cylinder is driven by one motor. The energy is provided by the batteries at the machine body rear. A simple improved design of the control system is also shown there. This new excavator can reduce energy consult greatly compared with traditional ones. Besides，it is a machine with zero-emission. Driven by motors instead of hydraulic system also reduces the cost during working and maintaining. The operation is convenient to the operators with easier control of motors. Labor intensity is reduced as a result.