Abstract: For high cost, poor sensitivity, complex protection setting calculation existed in current protection methods for shunt capacitor band in mine-used reactive power compensation device, characteristics of capacitor current distribution and fault were analyzed when shunt capacitor bank in mine-used reactive power compensation device broke down, and conclusions were gotten including that three-phase unbalanced grounding capacitor current would result in non-zero zero-sequence current when fault occurred, and zero-sequence current of non-fault capacitor bank was different with the one of fault capacitor bank. According to above conclusions, a protection method for shunt capacitor bank in reactive power compensation device was proposed which took zero-sequence current as criteria. The simulation results verify effectiveness and feasibility of the method.