Abstract: During the manufacturing process of composite materials,manufacturing defects such as adhesive delamination and holemaking delamination will inevitably occur.Delamination damage is an important damage form of composite materials,which seriously affects the mechanical properties of composite materials.In this paper,a variety of experimental studies on the mechanical properties of composite materials with prefabricated defects are carried out.Through comparative analysis with intact composite materials,the influence of manufacturing defects on the properties of composite materials is established,which can provide support for composite structure design.