Optimal reallocation design of military warehouse was put forward, which carried on a class-based L-shaped zone oriented optimization of stacker at leisure, to improve delivery speed and running stability of military Automatic Storage & Retrieval System (AS/ RS). According to user's requirement, the program automatically generates classbased L-shaped zone information, conducts stacker to judge and move the goods one by one, so that all goods ordered in accordance with the L-shaped zone, and ultimately accomplish the optimization progress. Specific examples were simulated with FlexSim software. Simulation results show that storage location is optimized and warehouse output efficiency is improved largely.