A tendo calcaneus suturing instrument, comprising: a first support and a second support that are of a U-shaped structure, a distance adjustment device, a first guide sleeve, a second guide sleeve, a first positioning tube, a second positioning tube and a tendo sheath cutter. An outer arm and an inner arm of the first support, and an outer arm and an inner arm of the second support are respectively provided with a first positioning hole, a first guide hole, a second positioning hole and a second guide hole and the first guide sleeve/the second guide sleeve is fixed by means of the first positioning hole/the second positioning hole and is matched with the first guide hole/the second guide hole. The first positioning tube/the second positioning tube provided with a through hole is arranged in the first guide sleeve/the second positioning sleeve or the tendo sheath cutter is arranged in the first guide sleeve and/or the second guide sleeve in a matching manner. The tendo calcaneus suturing instrument can simplify the surgical procedure, improve the surgical effect and relieve pains of a patient.
