A conceptual medical robotic system applicable for establishing surgical platform in the process of minimally invasive spine surgery (MISS) is proposed in this paper. According to the requirement of MISS operation, a five-degree-of-freedom (5-DOF) operating mechanism is designed and developed for such applications, and a detailed analysis has been performed for the robot involving the issues of kinematics, control and navigation. In view of the physical constraints imposed by mechanical joints, the operating mechanism is determined. Moreover, the kinematic analysis is carried out via the Denavit-Hartenberg (D-H) representation, and the control system is briefly introduced. Based on the principle of volume reconstruction and Windows programming technology, the surgical navigation system is established. At last, the experimental results made for the prototype illustrate the system well. This research will lay a good foundation for the development of a medical robot to assist in MISS operation.