Disclosed is a flexible surgical instrument system (100), comprising a flexible surgical instrument (10) composed of a distal structural body (11), a proximal structural body (12), a driving transmission mechanism (13) and a middle connecting body (14), wherein a surgical end effector (111) is located at a distal end of the distal structural body (11), a proximal end of the distal structural body (11) is linked to the middle connecting body (14), and the driving transmission mechanism (13) is linked to the proximal structural body (12) via the middle connecting body (14); the distal structural body (11) comprises at least one distal structural segment (112, 113), wherein each distal structural segment (112, 113) comprises a distal fixing disk (115, 118) and structural backbones (116, 119); the proximal structural body (12) comprises at least one proximal structural segment (120, 121), wherein each proximal structural segment (120, 121) comprises a proximal fixing disk (122, 126), structural backbones (124, 128), and driving backbones (125, 129); and the driving transmission mechanism (13) comprises an introducing part, a driving part, and a reversing part.