Abstract: An inner surface coating method for a piping having a step of causing an adhesive agent or a lining material to adhere to a curved portion of a pipe and sticking a reinforcing material transported by gas flowing inside the pipe at a constant flow speed of 1 to 120 m/sec to the adhesive agent or the lining material, and an inner surface coating device having a reinforcing material supplier using a reinforcing material, dispersion unit constituted by a closed primary dispersion tank for mixing the reinforcing material from a supply tank with gas supplied under pressure from a blower and by a closed secondary dispersion tank incorporating a dispersing rotary blade rotated by reinforcing material mixed gas supplied under pressure from the primary dispersion tank.