A novel 3-PRS with three degree of freedom (3-DOF) parallel mechanism is designed. Its inverse kinematics mathematical model was built. The main constraint of the mechanism was given. The sectional drawing and three dimensional (3D) solid drawing of the working space were generated by using the Monte Carlo method under different parameter conditions. The effect law of parameters on the working space of mechanism is analyzed, which provides the foundation for parameter selection and optimization design of this mechanism.