The coal winning machine is the core of the fully mechanized equipment of a complete set of compressors, and its work is reliable the quantity of coal. Electric traction shearer is dominated by electricity, and the incidence of electrical fault has been high, so the electric fault judgment and the research of coal mining is the effective measure to improve the reliability and stability of shearer. As Taikuang brand 700 electric traction shearer an example, by studying the usual electrical failure, try to analyze the causes of failure, find out processing method.