The invention relates to the field of rail transit, in particular to a groove cutting machine, a groove cutting machine for repairing a sleeper, and a railroad sleeper repairing method. The groove cutting machine comprises a limiting mechanism and a cutting mechanism, wherein the limiting mechanism comprises a limiting groove, a limiting insertion plate and a limiting stopper, the limiting insertion plate is inserted into the limiting groove, and is connected with the limiting stopper through an adjustable connecting piece, the thickness of the limiting insertion plate is the same as the width of the limiting groove, the limiting stopper is used for limiting the inserting depth of the limiting insertion plate in the limiting groove, the cutting mechanism comprises a cutting gear and a bracket, the cutting gear is mounted on the bracket through a rotatable connecting pipe, and the limiting insertion plate is fixedly connected with the bracket. The limiting insertion plate is inserted into the limiting groove to limit the cutting position, the limiting stopper is connected with the limiting insertion plate, with the gradual insertion, the limiting stopper is in contact with the limiting groove to stop the limiting insertion plate from insertion, concrete with cracks, arranged around the sleeper, is cut off through cutting a groove, the groove is filled and repaired, and the cracks around the sleepers are eliminated.