Abstract: Aiming at the problem of rock mass quality evaluation of underground mining engineering， taking the rock mass of the 3 000 m level middle section of Zaozigou Gold Mine as the research background， the entropy weight method is used to determine the weight of the evaluation index，and a five-element set pair analysis model based on the entropy weight method is constructed. Five indexes of rock uniaxial com‐ pressive strength，RQD index，joint spacing，joint state and groundwater condition are selected to evaluate the quality of surrounding rock. The results show that the diorite porphyrite in roadway is hard-hard intru‐ sive rock，and the quality grade of surrounding rock in its distribution section is Grade II. The slate belongs to hard-weak metamorphic rock，and the quality grade of its distribution section is relatively low，mostly Grade III. The evaluation results of the set pair analysis method are in good agreement with the RMR classi‐ fication results，and can intuitively reflect the degree of closeness between the evaluation rock mass and each grade standard. It is proved that the method is reasonable and feasible for the rock mass quality evalua‐ tion of underground mining engineering.

Key words: quality evaluation of surrounding rock, entropy weight method, set pair analysis, gold mine