Using robotic surgery system in the transpedicular screw path drilling would be helpful for alleviating the burden of surgeons and guarantee the correctness, stability and safety of operations. Focusing on transpedicular fixation operation, the robotic spinal surgical system RSSS-II was designed and developed. Firstly, a 6 degree of freedoms in-serial surgery robotic arm and a bone drilling device with force sampling were designed to meet the requirements of spinal surgeries, such as the operational safety, the range of the operation area, the positioning of patient and installation space issues. Secondly, for the precise control of robot in positioning and path drilling process, some key technologies were studied and then the image navigation system was built. Finally, the safety, accuracy and feasibility of developed robotic spinal surgery system RSSS-II we demonstrated through series of experiments. The experimental results show that the accuracy of the system can satisfy the clinical requirement.