Abstract: In the process of machine operation，due to influence of various factors，electrical equipment sometimes cannot work normally，which requires electrical equipment repair personnel can accurately grasp troubleshooting of electrical lines.Fault reasons of electric line for machine were analyzed.Steps and methods of maintenance for electrical circuit fault were briefly introduced.Different advantages with various methods were stressed.It is conducive to equipment repair personnel to adopt suitable and effective method of fault repair according to different fault phenomena，in order to solve practical problems quickly and accurately.