Abstract: Based on the optimization theory of material flow-direction and flow rate and simulation system,the gravity circular projection model and optimization model of flow-direction and flow rate for overcast stripping technology were proposed. The efficiency of overcast stripping technology can be improved by planning the optimal distribution of raw materials and optimizing the transportation order and path of waste. Taking Heidaigou surface mine as an example for this study,the three-dimensional model of unit body was constructed,and the fitting functions of the time-consuming probability distribution under various work contents and operating conditions were calculated. The simulated calcula- tion and analysis results show that the relation between the swing angle and time consumption of dragline conforms to the concave function non-linear correlation,and “ variance distance dumping” should be adopted. Also,the efficiency of dragline reaches the highest point when bench height is 13 m and it is unnecessary for dragline to do bench expan- ding work itself when dumping volume is adequate.