Abstract: Based on the analysis of the problems in available cutoff grade optimization methods, the paper proposes a dynamic programming optimization model for cutoff grade and describes its application in solving practical problems and its algorithm.The model considers the mining order and the grade distribution in different deposit sections and has realized the time-space dynamic combination of the cutoff grade in underground mining.Based on the mathematical model established, a corresponding computer application system has been developed and applied in a copper mine in Africa.

Key words: Cutoff grade, Dynamic programming, , Optimization