To resolve the contradiction between long-term economic benefits generated by coordinating mining technology and short-term profits affected by changing mining sequences, we used the basic principles of surface mining to optimize the mining sequences of two adjacent open pits. We first analyzed the characteristics of coordination mining technology and influencing factors for unifying stopes, then proposed an optimization criterion about mining district dividing schemes, also built optimization models about forms of stope and dump and gave a method to calculate the time of unifying stopes, and finally proposed an method to optimize forms of stope and dump after stopes were unified. The proposed models were verified through an engineering example. The results show that optimizing forms of stope and dump can reduce overburden, increase internal dump space reasonably, and enhance economic benefits of open pits in the process of unifying stopes.