Based on the risk assessment technology, drought risk for winter wheat in Yunnan Province was studied, the pivotal period of winter wheat yield reduction caused by drought was set and such index as drought intensity, yield reduction risk, disaster resistance and drought loss comprehensive risk were calculated.Thus, Yunnan Province was divided into different winter wheat drought risk regions.The paper pointed out that from inside to outside of Yunnan Province, the risk of losses caused by drought for winter wheat gets higher.