The seaming device in the hydraulic coiling machine is generally used to avoid the leakage of the office medium and the intrusion of external dust and foreign matter. The hydraulic system of the coiling machine plays the component of the seaming effect, that is, the seaming part, the seam in the hydraulic system of the coiling machine The leakage inside the piece will cause the volume rate of the hydraulic system to drastically decrease, which will not reach the required office pressure. The intrusion of fine dust particles in the system will cause or aggravate the wear of the friction pair of the hydraulic components of the bending machine, further causing leakage. The seaming part and the seaming device in the hydraulic system of the coiling machine are part of the hydraulic installation. The reliability and service life of the seaming part in the hydraulic system of the coiling machine is a key indicator to balance the quality of the hydraulic system.