This paper deals with the parameters design for 7 degrees of freedom surgical robot for hysterectomy. By analyzing of the surgical environment and characteristics of minimally invasive surgery for hysterectomy, the basic requirements for the design of the robot are presented; and optimizing of the robotic links' length is conducted based on these requirements. Through analyzing the surgical robotic structure, we establish the coordinate systems attached to robotic arms, and use the D-H method to derive the forward and inverse kinematics. The workspace of the surgical robot by using Monte Carlo method is discussed, and the result shows that the workspace covers all the surgical requirements. We divide the robot into two parts in structure, the first part is the preoperative positioning mechanism and the second part is a remote center mechanism (RCM). The links' length of first part can be optimized by using Jacobian matrix, we use the manipulability as the evaluation index to calculate the objective function; by using POWELL algorithm, the optimal links' length of the first part are obtained. We also find the manipulability of RCM are independent of links' length. The optimization results show that the robot has good operability at preoperative positioning and it meets the requirements of the robot flexibility for the hysterectomy.