The invention discloses a connecting tool of a clamping and pressing mechanical connector. The connecting tool of the clamping and pressing mechanical connector comprises a hydraulic cylinder clamping mechanism and a hydraulic cylinder opening and closing mechanism, wherein the hydraulic cylinder clamping mechanism is divided into a left part and a right part, and the left part and the right part comprises a left clamping claw, a right lamping claw, left hydraulic cylinder pistons, right hydraulic cylinder pistons and a left hydraulic cylinder base, wherein the left clamping claw, the right lamping claw, the left hydraulic cylinder pistons, the right hydraulic cylinder pistons and the left hydraulic cylinder base are arranged from front to back respectively; a plurality of clamping hydraulic cylinders and a plurality of opening and closing hydraulic cylinders are respectively installed on the base; the left hydraulic cylinder base is integrally hinged to a right hydraulic cylinder base; the front end of each left hydraulic cylinder piston and the front end of each right hydraulic cylinder piston are connected with the left clamping claw and the right clamping claw; the left clamping claw and the right clamping claw are respectively provided with a plurality sets of locking mechanisms, and are fixed together through the locking mechanism; the hydraulic cylinder opening and closing mechanism comprises an opening and closing hydraulic cylinder and a balance valve sleeved on the upper portion of the opening and closing hydraulic cylinder; the balance valve is connected with an external power source. The connecting tool of the clamping and pressing mechanical connector ensures that the clamping and pressing mechanical connector is fast and reliably installed, and is stably installed in the installing process, and improves the safety of the installment of the clamping and pressing mechanical connector.