Aiming at the difficulty of quantitative calculation of qualitative evaluation index of blasting safety in open-pit mine, a blasting safety evaluation model of open-pit mine based on combination weighting and interval approximation method was proposed to improve the accuracy of the evaluation results. Firstly, combined with the actual blasting engineering, 15 influencing factors were selected to construct a safety evaluation indicator system of open-pit mine blasting. Secondly, based on the idea of combination weighting, the subjective and objective weights calculated by the order relation analysis method (G1 method) and the improved indicator correlation weight determination method (improved CRITIC method) were coupled to obtain the comprehensive weight of the indicators. Then, based on the principle of interval approximation, the number of evaluation intervals of the indicators was determined, and the blasting safety level was comprehensively judged by calculating the deviation distance of a single indicator and the comprehensive deviation distance. Finally, taking 5 open-pit mine blasting cases in Hunan Province as the research object, the combination weighting and interval approximation method model was applied for comprehensive analysis. The results indicate that the blasting safety level of all five mines are "relatively safe", and the evaluation results are in line with the actual situation, verifying the applicability of the model in the blasting safety evaluation of open-pit mines.