The application of current differential protection on EHV transmission lines is mainly affected by the distributed capacitance current. Such an effect is even more significant in four-parallel lines due to the increased number of circuits and increased amount of mutual distributed capacitance. Based on theπ model of transmission lines， this paper proposes to decouple the four-parallel lines capacitance current compensation formula by utilizing the six-sequence component method and presents a time domain solution to compensate the capacitance current on four-parallel lines. Simulation result by PSCAD/EMTDC shows that this new capacitance current compensation scheme can effectively enhance the performance of current differential protection.