The purpose of the present invention is to provide a method for repairing a side gutter on the road. The method for repairing a side gutter on the road includes a step of installing a planing machine (12) on a side gutter (4) which is a repairing target; a step of planing and removing a repair surface of the side gutter (4) by using the planing machine (12); a step of placing repair mortar on a planed surface (5) of the side gutter (4) of which the surface is removed at a fixed depth by the planing machine (12); a step of flattening the upper surface of the repair mortar (6) charged in the planed surface (5) of the side gutter (4); and a step of curing the repair mortar (6) for a predetermined time.
