28  indexes  were  chosen  from  5  aspects  (rock  quality  of  slope,  slope  morphology,  human  factor,  safe  management  of  slope  and  other factor), and safe index system of rock slope of open-pit mine was established. Based on comprehensive fuzzy evaluation, weights of all indicators were determined through adopting analytical hierarchy process and Matlab program. Through adopting comprehensive fuzzy evaluation, safe index system was compounded and fuzzy evaluating model was established, and then comprehensive fuzzy evaluation was  carried  out  against  specific  situation  of  Saindak  open-pit  mine. Evaluating  result  is  that  rock  slope  of  Saindak  open-pit  mine  is  relatively safe, reflecting actual situation, which indicates this evaluating model is reasonable and reliable.