Abstract: In order to overcome the limitation and deficiency of the existing evaluation methods of coal mine safety, based on the comprehensive evaluation of coal mine safety state on the basis of matter-element extension method, the variable weight theory is used to modify the index weight, and a safety evaluation model of coal mine based on variable weight matter-element extension is constructed by replacing the maximum membership criterion with proximity degree.At the same time,combined with the sensitivity analysis,this paper points out the influence of the evaluation object on the weight and the evaluation result and obtains the sensitivity of the evaluation index.The application results show that the variable weight method can reflect the real safety state of coal mine effectively, and the effect of the variable weight method on abnormal index will not be further amplified; the average monthly training time of employees is an sensitivity index that affects the safety status of coal mines, thus realizing the timely screening of sensitive links; the safety grade of coal mine based on this model is relatively safe and tends to the safety level to a large extent, which is consistent with the results obtained by other methods, the existing research samples are verified,and the influence degree of comprehensive safety state grade to be evaluated with the change of each index is also given.