With the development of modern technology, fiberglass composite materials are widely applied. The advantages of fiberglass reinforced composite materials are high strength and light weight. In order to produce a prefabricated fiberglass composite, a machine chart was drafted for weaving the 3D fiberglass fabric with five layers. The obtained five-layer 3D fabrics were composited with polyurethane matrix. Afterwards, the performance of the prefabricated composites was tested and the optimal ratio of fiberglass to matrix was determined by statistical analysis.