Abstract: In recent years, with the development of new energy sources, lithium-ion battery (LIB) has become more and more important in the fields of electric vehicles and energy storage. As one of the four key materials in the lithium-ion battery, the morphology, size and preparation process of the diaphragm have an important influence on the performance of the battery. The good mechanical properties and chemical stability of polyolefin diaphragm provide good electrochemical properties for Lib, and the production cost of polyolefin diaphragm is lower, non-toxic and so on, as a result, it is an important raw material for commercial lithium-ion battery membranes. However, the thermal stability of polyolefin is poor, and the electrolyte wettability is low. The morphology and structure of the membrane can be modified by coating or grafting to improve the overall performance of the battery. In this paper, the methods of modification of polyolefin membranes are summarized in the light of the related research work in the field of lithium lithium-ion battery, which can provide important reference for the development of polyolefin membranes, the development trend of polyolefin membrane in the future was summarized.