Abstract: In view of low-voltage kinds of load side of coal mine power network,the paper selected eight influencing factors on voltage level of coal mine power network,then used analytic hierarchy process to build three-layer evaluation structure,gave calculation methods of weigh of each layer,and used the method of grey theory and fuzzy comprehensive evaluation to analyze influence degrees of each factor,which could get accurate evaluation of low-voltage possibility of coal mine power network.The example analysis proved the validity of the method.