The relevant factors affecting the sealing capacity of the clamp are analyzed. The factors affecting the circumferential sealing capacity of the clamp include the distance between the sealing ring and the pipe, the friction factor, and the distance between the metal support ring and the pipe. The factor affecting the axial sealing capacity of the clamp is friction factor. Based on the sealing structure of the clamp, the finite element model and simulation calculation of the factors affecting the sealing capacity are carried out by the finite element software Abaqus. The simulation results are analyzed. The increase of the friction factor, the distance between the ring and the pipe, and the distance between the seal ring and the pipe is not conducive to enhance the circumferential sealing capacity of the repair clamp. The relevant parameters can be appropriately reduced during the design. The friction factor is of little effect on the axial sealing capacity of the repair clamp, and the influence of the friction factor on the axial sealing can be ignored in the design. The work can provide useful guidance for the design and application of clamp sealing structure.