A method of measuring capacitive current is proposed based on simultaneously adjusting the arc-suppression coil inductance and damping resistor to keep the system zero-sequence voltage phase unchanged. To limit neutral displacement voltage in arc-suppression coil grounding system, the parallel resistance is often adopted to improve the damping rate of system. The zero-sequence voltage phase keeps unchanged by increasing or decreasing the arc suppression coil damping and adjusting arc-suppression coil inductance, capacitive current of system can be calculated by amplitude ratio between the zero-sequence voltage. It is simple and convenient to measure by the method. Simulation model is simulated by Matlab, which shows that the method has high measuring accuracy.