Minimally invasive surgical space, especially narrow workspace such as throat and oral cavity, require much higher manipulative dexterity. The existing robotic surgical robots still suffer from the inflexible end effector, the coarse robot volume. In this paper, we propose a new minimally invasive surgical manipulator. It consists of a flexible joint and a fast connect interface. The flexible joint, comprised of an elastic machined spring and a rigid base rod, can achieve Omni-orientational bending movement with a variable curvature through adjusting the coupling length between the elastic machined spring and the rigid base rod. The fast connect interface, enabling a quick connection between the surgical manipulator and the drive house, can improve the operative efficiency on surgery. Kinematics and workspace of the flexible joint is presented, and the preliminary experiments demonstrate the bending reachability of the surgical manipulator under different bending curvature to adapt for narrow workspace.