Abstract: Flax are the main oil crops in Datong ang Shuozhou,field crops are also important,in the oil crops in the oil flax known as the ＂Oil Queen＂.According to the survey in 2009 in Datong and flax growing area of about 30000 hm2 accounting for more than 70% of oilseeds,with an average yield of 705~1250kg/hm2 but the de velopment is very uneven across The reason is mainly arid climate,precipitation uneven,barren land,mixed varieties,planting high-quality,low input,extensive farming and insect pest management seriously.