Powdery mildew is one of the main diseases in flax,due to climate warming on earth,the disease bursted and prevailed in the main cultivated areas occasionally,which severely disrupted the yield and quality of flax. This article summarized the progresses of powdery mildew in flax,the incidence characteristics and regularity of the disease,identification and selection of resistant germplasm resources,inheritance of resistance and resistant genes,control strategies for the disease. The problems in recent research were analyzed and suggestions were made,which could provide references for associated research.