The invention relates to the technical field of water construction rigging equipment, in particular to an immersed tube transverse moving, mooring and cable tying tripper and a cable tying and cable loosening method thereof. The cable tying tripper comprises a tripper body and a tripping arm which comprises a connection end and a hook end used for hooking and cable tying; the hook end is hinged toon end of the tripper body; the other end is connected with the other end in a detachable manner, and can rotate around the hook end; a connection structure is further arranged at the other end of the tripper body; and the portion, making contact with a belt dragging mooring rope, of the hook end of the tripper arm is of an arc-shaped structure. During cable tying, the tripping arm rotates aroundthe tripper body to be opened, the belt dragging mooring rope can easily penetrate into the tripping arm, the tripping arm is closed, and a tripping buckle shackle is buckled to achieving cable tying; when belt dragging cable loosening is completed, the tripping buckle shackle is manually knocked on, the tripping arm is automatically opened under the acting force of the self weight of a mooring rope, and cable loosening is successfully completed. The problems that cable tying frequently happens to a large steel wire rope, and fast cable loosening is difficult are solved, the labor intensity for cable tying of a worker is greatly reduced, and the work efficiency of the worker is improved.