An electric power coaxial cable welding tool comprises a cable welding base device and a plug device. The cable welding base device comprises a cable welding base, a fixing groove is formed in the cable welding base, a rotating plate is installed on the upper portion of the cable welding base, one side of the rotating plate is hinged to the cable welding base, and an arc-shaped leaf spring is installed at the bottom of the rotating plate; just by rotating the rotating plate, connection between the arc-shaped leaf spring and a first central spindle can be achieved, and meanwhile fixed connection between the cable welding base device and the plug device can be achieved. The operation process is simple, and the new current transformer replacing speed is increased. The arc-shaped leaf spring is of an arc-shaped plate structure, as the arc of the arc-shaped leaf spring faces downwards, the arc-shaped leaf spring reserves a certain compression space, and when the arc-shaped leaf spring is matched with the first central spindle, the arc-shaped leaf spring can generate a certain pressure between the arc-shaped leaf spring and the first central spindle through compression so as to reduce the contact resistance.