To provide a method for manufacturing a cast-iron-pipe having a synthetic resin coating film for preventing corrosion on an inner peripheral surface by coating the inner peripheral surface of the cast-iron-pipe used as a water supply pipe and a sewerage pipe with the synthetic resin film.

As the water supply pipe or the sewerage pipe, the cast-iron-pipe obtained by flowing-in a steel sheet integrally formed by bending an iron plate sheet and welding a contact part, and a cast in the melting state to a centrifugal cast metal die and casting it is known. The cast-iron-pipe is proposed taking into consideration that quality of city water is reduced by oxidizing and corroding the inside and contaminating the inside of the pipe by depositing a foreign matter as such a steel pipe is used. A synthetic resin powder is injected to a pipe inner diameter after the cast-iron-pipe is heated to a melting temperature of the synthetic resin material to form the synthetic resin coating film on an inner peripheral surface of the cast-iron-pipe. Thereafter, the cast-iron-pipe is rotated and the inner peripheral surface of the cast-iron-pipe is smoothly coated with the synthetic resin coating film at the uniform thickness by centrifugal force generated by the rotation.