The invention discloses a perforating method for a pipeline (10). The perforating method comprises the following steps of: (a) fixing a positioning short section (30) on the outer surface of a to-be-removed area of the pipeline (10); and (b) enabling a perforating tool of a perforating device to penetrate through the positioning short section (30) to perforate the pipeline (10). The perforating method also comprises the step of fixedly arranging at least one reinforcing rib (13) on the outer surface of the to-be-removed area of the pipeline (10) prior to Step (a). Since the reinforcing rib is arranged on the to-be-removed area of the pipeline prior to perforation in the perforating method, the stiffness of metal in the to-be-removed area on the pipeline is increased, deformation of the removedmetal can be avoided effectively during perforation, and smooth perforation can be ensured.