According to the exploration data and results of indoor tests on rock samples from various strata in some mine,and based on a synthetic consideration of the characteristics of slope engineering construction,the strength of rock in the mine was calculated using three kinds of rock strength reduction methods,including medium-small value and medium-large value method,inner friction angle reduction factor method as well as engineering empirical factor strength reduction method,the mechanical parameters and deformation index of slope rock were determined by use of the information entropy weighting method,which provided essential data for analysis and evaluation of strength,deformation and stability of slope engineering in the mine.