This thesis presents the design of a novel compliant constant-force gripper mechanism which based on buckled fixed guided beam. Firstly, a review of the background and the limitations of the existing constant-force mechanism are proposed. Secondly, a prototype of constant-force mechanism is designed to verify the constant-force output’s principle. Next, a complete constant-force gripper mechanism is designed. At last, by summarizing previous experience, a 3-D printed polymeric scheme is carried out to do the application test. During this process, the combination of a positive stiffness and a negative stiffness mechanism are used to provide the zero stiffness. The negative stiffness is obtained by using an inclined bistable buckled fixed-guided beam. The positive stiffness is provided by a straight thin wall beam. Normally, during the manipulation, both the displacement control and force control are required to protect the target object. Therefore, one specific advantage of the constant-force mechanism is that it can eliminate the needs of forcedisplacement combined control algorithm. The software ANSYS APDL and MATLAB are used to solve the force displacement relationship. Three different case designs will illustrate the design method in details. Several experimental studies are carried out to verify the theoretical model.