Surgical knife

The utility model discloses a surgical knife. The surgical knife comprises a grip body, a knife body, a shape memory alloy wire, a spring and a pulse circuit, wherein a cavity is formed in the grip body; one end of the knife body is movably arranged at one end of the grip body, and the knife body can do linear reciprocating motion relative to the grip body; one end of the shape memory alloy wire is fixed to the inner wall of the cavity, and the other end of the shape memory alloy wire is connected with one end of the knife body; the shape memory alloy wire is sleeved with the spring, one end of the spring is connected with the other end of the shape memory alloy wire, and the other end of the spring abuts against the inner wall of the cavity; the output end of the pulse circuit is electrically connected with the shape memory alloy wire. Compared with the prior art, as a breakthrough improvement, the shape memory alloy wire replaces machines like a common motor as a driving element. The surgical knife is simpl