Abstract: For failure of fault line selection methods based on steady-state component in resonance grounding system, three kinds of methods were analyzed from the perspective of transient component including zero-sequence energy method, wavelet transform method and enhancing wavelet packet method. Fuzzy comprehensive evaluation method was introduced to integrate the three kinds of methods, and AHP method was used to determine weights of the three methods. The simulation conclusion shows that the reliability of zero-sequence energy method and enhancing wavelet packet method are better, but wavelet transform methods has false conclusion, with poor reliability; The fuzzy comprehensive evaluation is not interfered by other error signal, and gives correct conclusion, which has strong reliability.