optical cable filling substance is an ideal optical cable filling material, which can prevent optical fibers from micro-bending loss caused by external stress field. Suitable viscosity, strong fluid density, can be filled at room temperature; After the water swelling block type: moisture absorption speed is very fast, high water absorption capacity, good characteristics of the block; Heat deformation retaining strip type: thermal expansion and cold contraction fast, uniform expansion, hardness is not enough not coke.