In a method for repairing a drainage pipe, a resin pipe can be placed in an existing drainage pipe connected between connection bodies such as manholes while being buried in the ground, without causing an elongation. The method involves supplying a corrugated resin pipe 5, which is made by forming, spirally or in a ring shape, ridge portions 5c of a hard resin on the outer wall of a soft resin pipe 5d, 5e in which a reinforcement material 5f that restricts an elongation in the pipe axis direction has been embedded, into the existing drainage pipe through the upper opening of either of the connection bodies; inserting the head of the corrugated resin pipe 5 thus supplied from a drainage pipe opening connected to either of the connection bodies; pulling the corrugated resin pipe 5 thus inserted into the drainage pipe from the other side of the connection body; and laying the corrugated resin pipe 5 over the entire length of the drainage pipe.