At present, the zero-sequence overvoltage criterion for disconnection of new energy grid-connected faults is set according to the unbalanced voltage during normal operation of the system that bypasses the direct grounding of the neutral point. The disconnection time is coordinated with the zero-sequence overvoltage of the transformer gap of the new energy access station. However, when a high resistance grounding short circuit occurs in the line or a fault occurs within the protection section II of the line, the strategy has the problem of large-scale misrepresentation of new energy. Therefore, this paper proposes an improved method of zero-sequence overvoltage fault splitting strategy that can reliably prevent new energy from misinterpreting trains in a large area, and designs the splitting criteria. Finally, the effectiveness of the strategy is verified by simulation and actual faults. The results show that the splitting strategy has high reliability and practicability.