Lightning strike is one of the major factors that affect the precision of traveling wave fault location devices. Identification of lighting strike is key to mitigate the lighting strike influences on the transmission lines. In comparison with short circuit currents， lighting fault currents are more acute in gradients and the non-fault phase currents carry much more transient energy in their traveling waves. Based on this， a new wavelet transform method is proposed to identify lighting faults by extracting the gradients of fault currents and transient energy in the non-fault phase currents. Also， the corresponding criteria are proposed. EMTDC simulation and experimental results verify the correctness of the proposed method.