PURPOSE: To grind the surface of a pipe body easily and smoothly by injecting a mixture of an abrasive and a solution into a rotating cylinder and vertically moving the pipe body made of aramid fiber-reinforced composite material and inserting it into the cylinder in sequence.

CONSTITUTION: A spiral groove 1 is formed on the inner face of a cylinder B with the inner diameter almost equal to the outer diameter of a pipe body A to be ground. This cylinder B is rotated around its axis, a mixture of an abrasive and a solution is injected into the cylinder B under this condition, and the pipe body A is vertically moved and inserted into the cylinder B in sequence. The surface of the pipe body A made of aramid fiber-reinforced composite material is ground by the abrasive in the mixture injected between the pipe body A and the cylinder B. The surface of the ground pipe body A is simultaneously washed with the solution in the mixture.