1. A clamp plier, comprising a fixed handle and a movable handle, wherein the fixed handle is connected with head side plates, a fixed head, a movable head and a rotating member are provided between the head side plates, the fixed head is connected with the movable head through a rotating shaft, a first elastic member is connected between the fixed head and the movable head, the rotating member comprises a positioning part and a cam part, a one-way retaining bearing is provided at a side of the positioning part or the cam part, the movable handle is connected with a tripping member, the tripping member is provided with a ratchet assembly, the positioning part is connected with the ratchet assembly, and a second elastic member is connected between the tripping member and a head side plate; the fixed head comprises a first cutting edge part, and the movable head comprises an acting part and a second cutting edge part, and the first cutting edge part and the second cutting edge part form a jaw; and the cam part and the acting part press against each other to drive a gap between the first cutting edge part and the second cutting edge part to be reduced or increased.