Abstract: In recent years, with the development of open-pit mining process equipment and the advancement of mining technology, the large-scale production scale has become the main development direction of global open-pit coal mines, and the expansion of production scale has complicated the design of mine production and the management of on-site production organization. Therefore, a reasonable production scale is very important for open pit production. In view of the current high-capacity and high-pushing strength of the Heidaigou Open-pit Mine, the north-south sub-zoning mining plan of the southern throwing blasting-drawing shovel dumping operation is reasonable after entering the second mining area due to changes in geological conditions. To determine the production capacity, a method for determining the reasonable production capacity of open pit mines by time-space deduction simulation is proposed. By analyzing the on-site factors affecting the mining process, setting the corresponding constraints, establelishing the constraint equation and the objective function between the various processes in the production process, using the space-time derivation method, the production links in the open pit mine are time-space deduction of 290, 300,310, 320 m/a for the connection steps of different processes under different advance speeds. The bottlenecks is found in the mining process and continuously optimized and upgraded to ensure the normal and efficient connection between different processes. The authors find out the bottlenecks in the mining process and continuously and optimized and upgraded them to ensure the normal and efficient connection between different processes. The research ruslts show that after the Heidaigou Open-pit Mine enters the second mining area, under the conditions of existing equipment and equipment, through the simulation of each process, the best propulsion strength of the mining area is 310 m/a; The combination of mining equipment capacity and cost efficiency, to determine the reasonable production scale of district mining is 3 2 Mt/a.This study provides technical basis and theoretical support for the smooth connection of the production of raw coal and the stable development of mine production capacity.