Abstract: Electron beam surface cladding modification technology has been widely used in engineering field, and the defect control of cladding layer has become a hot research topic. According to the principle and characteristics of electron beam surface cladding modification technology, the causes of various defects in cladding layer were summarized. Aiming at various defects, the corresponding improvement measures were summarized, and the research on defect control of electron beam cladding layer was prospected.