Abstract: Auto-reclosing is a very important equipment that can improve reliability of power supply system and guarantee security operation of power line,so the auto-reclosing is widely applied in transmission line.In allussion to the misjudgment of voltage criterion of auto-reclosing,the paper put forward a method of fault recognition which applied fuzzy neural network(FNN) to recognize the faults of single phase auto-reclosing.It built up a model of fuzzy neural network with two-input and one-output,which was used to recognize transient faults and permanent faults.Using the method of gaining fuzzy rules from samples and Matlab software,it simulated the method.The simulation result verified the feasibility and accuracy of the proposed method.