A multi-degree-of-freedom flexible surgical instrument, comprising a flexible continuous body structure and a driving unit, wherein the flexible continuous body structure comprises a distal structural body, a proximal structural body and a middle connecting body; the distal structural body comprises a first distal structural segment and a second distal structural segment, the first distal structural segment comprising first distal spacing disks, a first distal fixing disk and first segment structural backbones, and the second distal structural segment comprising second distal spacing disks, a second distal fixing disk and second segment structural backbones; the proximal structural body comprises a proximal structural segment, and the proximal structural segment comprises proximal spacing disks, a proximal fixing disk and second segment structural backbones; the second segment structural backbones located on the proximal structural segment are securely connected in one-to-one correspondence to or are the same as the second segment structural backbones located on the second distal structural segment; the middle connecting body comprises channel fixing plates, channel fixing blocks, first structural backbone guide channels and second structural backbone guide channels, the channel fixing blocks being located between the two channel fixing plates, the first structural backbone guide channels being securely connected between the channel fixing blocks and the channel fixing plate near the distal structural body, and the second structural backbone guide channels being securely connected between the two channel fixing plates; one end of the second segment structural backbone (133,163) is securely connected to the proximal fixing disk, and the other end of the second segment structural backbone (133,163) passes through the proximal spacing disks, the second structural backbone guide channel, the first distal structural segment and the second distal spacing disks in sequence and is then securely connected to the second distal fixing disk; and the driving unit comprises a proximal structural segment driving handle and a first distal structural segment driving assembly, the proximal structural segment driving handle being securely connected to the proximal fixing disk, the first distal structural segment driving assembly being located between the two channel fixing plates, and an output end of the first distal structural segment driving assembly comprising two sliders moving in opposite directions along a straight line, and one end of the first segment structural backbone being securely connected to the slider, and the other end of the first segment structural backbone passing through the channel fixing block, the first structural backbone guide channel and the first distal spacing disks in sequence and being then securely connected to the first distal fixing disk. the flexible continuous body structure comprises a distal structural body, a proximal structural body and a middle connecting body; the distal structural body comprises a first distal structural segment and a second distal structural segment, the first distal structural segment comprising first distal spacing disks, a first distal fixing disk and first segment structural backbones, and the second distal structural segment comprising second distal spacing disks, a second distal fixing disk and second segment structural backbones; the proximal structural body comprises a proximal structural segment, and the proximal structural segment comprises proximal spacing disks, a proximal fixing disk and second segment structural backbones; the second segment structural backbones located on the proximal structural segment are securely connected in one-to-one correspondence to or are the same as the second segment structural backbones located on the second distal structural segment; the middle connecting body comprises channel fixing plates, channel fixing blocks, first structural backbone guide channels and second structural backbone guide channels, the channel fixing blocks being located between the two channel fixing plates, the first structural backbone guide channels being securely connected between the channel fixing blocks and the channel fixing plate near the distal structural body, and the second structural backbone guide channels being securely connected between the two channel fixing plates; one end of the second segment structural backbone (133,163) is securely connected to the proximal fixing disk, and the other end of the second segment structural backbone (133,163) passes through the proximal spacing disks, the second structural backbone guide channel, the first distal structural segment and the second distal spacing disks in sequence and is then securely connected to the second distal fixing disk; and the driving unit comprises a proximal structural segment driving handle and a first distal structural segment driving assembly, the proximal structural segment driving handle being securely connected to the proximal fixing disk, the first distal structural segment driving assembly being located between the two channel fixing plates, and an output end of the first distal structural segment driving assembly comprising two sliders moving in opposite directions along a straight line, and one end of the first segment structural backbone being securely connected to the slider, and the other end of the first segment structural backbone passing through the channel fixing block, the first structural backbone guide channel and the first distal spacing disks in sequence and being then securely connected to the first distal fixing disk.