Abstract: The forming process, mechanical property, flame retardancy and low toxicity of the glass fiber reinforced siloxane modified vinyl resin composites are studied. It is found that when the thickness of the laminate is less than 40 mm, the composite material can be formed by vacuum assisted resin infusion(VARI) in the primary forming, and the formation is fine. When the thickness of the laminate is more than 40 mm, the composite material can be formed by VARI in the secondary forming. The mechanical properties of the modified composites decrease by less than 10%. The properties of flame retardancy and low toxicity of the siloxane modified vinyl resin composites are studied by oxygen index, low flame seeding, smoke toxicity, normal temperature toxicity and high temperature toxicity tests. The results show that the synergistic flame retardancy of the phosphorus and silicon significantly improves the flame retardancy of the composite, and that the oxygen index increases from 24.5% to 38.0%. The low flame retardancy can meet the service conditions of the wall and ceiling lining. The low toxicity and low smoke properties of the siloxane compounds significantly reduce the smoke and toxicity of the composites. The smoke density of the siloxane modified vinyl resin composites is 189, and its toxicity is low, which can be used in a closed environment.