The invention discloses an incision surgical knife which comprises a guide pipe, an elastic element, an operating handle, a first guide wire and a saccule, wherein the guide pipe is in a hollow structure, is provided with a side hole, a groove, a thread eye and a gas injection water injection hole which are sequentially arranged from the front end to the terminal end; the elastic element is embedded in the groove, and the rear end of the elastic element is fixed with the guide pipe; the operating handle is sheathed outside the guide pipe and can slide along a guide pipe shaft; the first guide wire is arranged in the guide pipe, the front end stretches out from a guide wire hole and is fixed with the front end of the elastic element, and the terminal of the first guide wire is fixed with the operating handle; and the saccule is fixed at the top of the guide pipe in a sealing way, and the side hole is arranged in the saccule. The operation incision knife provided by the embodiment of the invention is designed specially for full resection of mucous membrane in minimally invasive surgery, thus full resection on a large-area mucous membrane can be rapidly and effectively carried out in an operation, viscera except the mucous membrane can be effectively avoided, peripheral viscera can not be damaged, surgical risk is reduced, and success rate of a surgery can be improved.