Abstract: Adopting the SURPAC 3D geological mining software，combining with the actual demands of Tongling Xinqiao Deposit，and based on the 3D digital mine model，the optimization of open-pit mining limit is made by the mathematical logic algorithms of L-G method. The results provide a data basis for increasing the economical benefits，and propose a rational recommendation for the more reasonable mining production in Xinqiao Deposit.

Key words: Open-pit mine, Limit optimization, 3D Modeling, L-G method, Surpac software