Guide cylinder connecting structure and connecting method thereof

According to the flow guide cylinder connecting structure and the corrugated pipe expansion joint connecting method, the flow guide boss is arranged through the connecting flange parent body, the connecting mode of the flow guide cylinder and the connecting flange is changed into bottom locking butt welding from lap joint angle welding, the welding seam forming quality is improved, and meanwhile the flow guide cylinder connecting structure and the corrugated pipe expansion joint connecting method are improved. And the risk of scouring thinning caused by a high-flow-rate medium can be effectively reduced. By arranging a plug welding structure penetrating into a flange base metal base body, the problem that a guide cylinder circumferential weld joint vibrates and cracks due to a guide cylinder cantilever structure is further solved, and the failure of equipment near a pipeline system caused by the falling phenomenon of the guide cylinder is avoided; and the safe service period of the metal corrugated pipe expan