The function of the Fiber Optic Splice Closure is to protect the optical fiber and optical fiber connector from impacts such as vibration, punching, bending, etc., and to prevent moisture. The splice box and the terminal box are different, and the fiber optic splice closure is fully sealed to be waterproof but it cannot fix the pigtail. The terminal box is not waterproof, the internal structure can be fixed on one side of the cable, one side can be fixed pigtails, in which the two ends of the optical fiber fusion, but the fiber optic splice closure is fiber optic cable and pigtail welding, the latter is the fusion between fiber optic cable. Therefore, the fiber optic splice closure should have the following properties: 1. Good sealing. Optical fiber transmission attenuation has close relationship with waterproof performance, so the fiber optic splice closure should have good gas-tight and waterproof performance, general requirements within 20 years can effectively waterproof, moistureproof and prevent the harmful gas invasion. 2. Good mechanical performance. The fiber optic splice closure must have certain mechanical strength to ensure that the optical fiber performance will not be affected when the pressure applied on the optical fiber joint reaches 70% of its strength. 3. Long-term corrosion resistance. At present, most of the cases of fiber optic splice closures are made of plastic products. In addition to corrosion resistance, the materials' aging resistance and insulation performance should meet the 20-year life requirements. 4. The fiber optic splice closure should be easy to disassemble and the material can be reused. 5. The fiber optic splice closure should be as light as possible to reduce the labor intensity and shorten the operation time. The fiber optic splice closure is suitable for the direct connection and branch connection of overhead, pipeline, direct buried and other laying methods of various structural optical cable. The box body is made of imported reinforced plastic with high strength and corrosion resistance. The terminal is suitable for the connection in the terminal room of the structural optical cable.