To take photos through airplane is an important technique by obtaining the crop information. However, the in the Big Data ages, it is a tough work to handle them well and to transfer them as available information. Massive past studies focused on the single target category classify method such as paddy rice. This project is entrusted by Chung Hsing Survey Company to help them carry out to build a multi-decision system. The system can automatically discern four corps: rice, corn, cauliflower and cabbage. The Rough-Set theory is used to resolve the problem. The layer-rules are used to process the four major corps. This system can effectively classify the corps on the farmland.