Abstract: In order to evaluate the effect of bench blasting accurately，the matter-element extension theory is applied，and 11 main factors that affect the bench blasting are selected as the index of evaluating the bench blasting，including loose coefficient，toe rate，back crack distance，blasting vibration，flying distance，detonator consumption，blasted volume per meter，the boulder yield，muck pile profile，environmental impact，and explosive consumption，so as to establish the matter-element extension model for comprehensively evaluate the bench blasting.In order to remedy the defect at failure of the correlation function caused by that the feature value may exceed the joint domain，the bench blasting effect levels standards and the evaluating planning index were normalized by the membership function to determine the classical domain，joint domain and the matter element and to eliminate the influence of dimension.The entropy-weight method was used to confirm the weight of evaluation indicator，reducing the influence of subjective factors，to calculate out the correlation level of the matter element to be evaluated and the evaluation grade.Then，according to the maximum incidence degree criterion，the effect of bench blasting was evaluated comprehensively.In order to study the effectiveness and practicality of the model，the model was applied to four times of bench deep-hole blasting in Hongshuitai field-leveling projects.After analysis and calculation，the comprehensive evaluation result of bench blasting effect was obtained.It can be seen from the results that the evaluation effect of the model is the same as the actual situation.This method provides a new method for comprehensively evaluating the bench blasting effect.

Key words: Matter-element extension model, Relational degree, Membership function, Entropy-weight method, Bench blasting, Effect evaluation