Abstract: There are many factors influencing the blasting effect of hard fault deep hole pre-split blasting in underground coal mine and it is uncertain.In order to improve the accuracy of the evaluation of the effect of deep hole pre-split blasting on hard faults, the evaluation index system of evaluating the effect of underground coal mine blasting from three aspects of blasting quality, construction safety and economic benefits is established by introducing the unascertained measure theory.The subjective weights determined by order relation analysis method (G1 method) and objective weights calculated by entropy weight method (EW method) are coupled into a comprehensive weight to improve the weight calculation model, and the confidence recognition criterion is used instead of the maximum membership criterion to adjust the rating judgment.By applying the improved evaluation model to the practice of deep hole pre-split blasting effect evaluation in Suncun Coal Mine, the corresponding comprehensive weights of blasting quality, construction safety and economic benefits are 0.503, 0.274 and 0.223, and the confidence degree is 0.856.The blasting effect grade of the coal mine is “good”.Some suggestions to improve the blasting effect are given from three aspects that the development of rock fissure, the range of crushing zone and blasting vibration.The research results show that the results of the evaluation model are highly consistent with the actual construction situation, which can provide a new reference for the evaluation of the effect of deep hole pre-split blasting on hard faults.