Abstract: According to the relationship between the electrical equipment current-carrying fault and contact resistance, loaded-current, surface environmental temperature and board dimension,this paper study and set up high-voltage electrical equipment current-carrying patch board fault temperature rise fault finite element approach, by means of heat transfer theory, build temperature rise model. According to a 35 kV current transformer loaded-current patch board heating-fault, this paper analysis by the ANSYS simulation calculation way,and research focus on current-carrying temperature rais effect of current size, surface environmental temperature and board dimension. Analytic result has important references for the current-heating fault judgment of the electrical equipment, and has important references for the manufactures selecting board dimension on high-voltage electrical equipment.