Transformer relay protection equipment misoperation when the transformer is ready to run in a substation. According to the fault wave graphics and data, error action of transformer relay protection equipment is caused by loss of magnetic inrush current closedown of second relay protection equipment. After investigating the magnetic inrush current closedown elements of second protection equipment in the technology documents, this paper analyses the magnetic inrush current criterion by mathematics method, points out the instability of hamming close degree fuzzy recognition theory. Aiming at its bug, this paper puts forward a multi-subordinate function criterion solution based on the combination of nerve network framework and hamming close degree fuzzy recognition theory.