Outdoor composite insulation products are made of glass fiber pull-out rod, silicone rubber and metal parts. Compared with traditional ceramic and glass insulators, they have the advantages of light weight, large climbing distance and small wind load. The pull-out and pultrusion process of the mandrel has the conditions for continuous production, and the insulation distance can be adjusted according to needs. It has good adaptability in areas with high altitude, heavy pollution, frequent bird damage and serious wet flash and ice flash. In recent years, the composite cross arm has been widely used in 10kV distribution network for its excellent lightning protection performance.