Disclosed is a flexible surgical instrument system (10), comprising a flexible continuum structure consisting of a distal structure (11), a middle connecting body (15) and a proximal structure (16) linked in sequence, and further comprising a transmission driving unit (21) linked to the proximal structure (16). The transmission driving unit (21) comprises a plurality of transmission mechanisms (22) respectively driving corresponding proximal segments (17, 18). The transmission mechanisms (22) can convert a pair of rotary motion inputs with axes parallel to each other into a pair of rotary motion outputs with axes orthogonal to each other. One of the rotary motion outputs with the axis parallel to the axes of the rotary motion inputs is used for controlling the direction of a bending plane of the proximal segments (17, 18), and the other rotary motion output with the axis perpendicular to the axes of the rotary motion inputs is used for controlling the bending angle of the proximal segments (17, 18) in the bending plane, so as to drive the proximal segments (17, 18) in the proximal structure (16) to bend or turn in any arbitrary direction, and to further drive distal segments (12, 13) in the distal structure (11) linked thereto to bend or turn in the opposite direction.
