To provide the molding method of a polymer porcelain tube with no position slippage of a covering rubber to an FRP core and no requiring of after-working for repair.

A tapered polymer porcelain tube is molded in such a way that a tapered hollow core member is arranged within a polymer porcelain tube molding mold 1, a covering forming material is filled in tapered covering forming spaces 1a, 1b around the hollow core member, then the mold 1 is heated to the prescribed covering forming material curing temperature to cure the covering forming material. The hollow core member is previously set so as to shift in the small diameter direction of the tapered hollow core member on the inside of the polymer porcelain tube molding mold.