A snakelike surgical instrument, comprising a handheld structure (2); an manipulating structure (1) comprising an outer frame (13) hingedly connected to the handheld structure (2) so that the manipulating structure (1) has a rotational degree of freedom (R1′) around a first axis and an inner frame (14) hingedly connected to the outer frame (13) so that the manipulating structure (1) has a rotational degree of freedom (R2′) around a second axis, the first axis and the second axis forming an angle; an end unit (4) connected to the handheld structure (2) by means of a connecting component (3) and comprising a tool supporting base (41) and a snakelike structure (40) connected to the tool supporting base (41), the snakelike structure (40) having degrees of freedom of motion (R1, R2) in the same direction as the manipulating structure (1); and a transmission unit (5) comprising a flexible transmission structure connected to the inner frame (14) and the snakelike structure (40). A mechanical transmission mode is used by the snakelike surgical instrument, the motion of a handheld side can be directly transmitted to the end unit (4), complicated force feedback control is avoided, and control is simple.