A finite element model of the three DOF high-stiffness robot was established, and its static and dynamic characteristics were analyzed. The influence of the brake action on the stiffness, natural frequency and steady-state response of the robot under external forces were compared and analyzed; experimental test analysis to the prototype was performed. The results show that the proposed brake structure scheme can increase the stiffness and natural frequency of the robot, reduce the end amplitude of the operating, and improve the dynamic characteristics of the robot when working.