Coating swelling-prevention mold

The invention provides a coating swelling-prevention mold. A layer twisting type optical cable secondary coating extrusion pipe type one-time extrusion moulding mold is provided. The high speed rotation need of high speed being 600 m/min and above of coating can be ensured, and the problem that in the high-speed production process, materials are accumulated in a mold core and swelling is caused can be solved. The mold comprises a mold core and a mold sleeve, a first taper closing-in cavity, a second taper closing-in cavity and center cylinder cavities are formed in the center of the mold sleeve from inside to outside, the taper of the first taper closing-in cavity is larger than that of the second taper closing-in cavity, the closing-in tail end of the first taper closing-in cavity is connected with the initial end of the second taper closing-in cavity, the closing-in tail end of the second taper closing-in cavity is connected with the initial end of the center cylindrical cavity, a center shaft of the mold c