A capacitive current measurement method of the distribution network is proposed based on Newton-Raphson Method. In the system of arc suppression coil and damping resistance grounding system, the Newton-Raphson method is of effectiveness and fast convergence calculation. After the damping resistance is changed, finding that the inductance of arc suppression coil which can keep constant neutral point voltage unchanged. On this basis, it is determined that the phase angle is constant between detuning size and total conductance of the system and the phase diagram is constructed. The accurate calculation of the capacitance and the ground electric conduction is realized. Finally, the capacitive current measurement is realized. By building the simulation model in Matlab and simulation experiment, the correctness of the proposed measurement method and higher accuracy of the measurement results are verified. This work is supported by National Natural Science Foundation of China (No. 51107143).