Abstract: A new spatial compliant parallel manipulator with 3-RPC used in precision positioning is presented and analyzed in this paper. By assessing the configuration of the manipulator based on the screw theory and thus obtains the movement screws and reciprocal screws of the manipulator, this paper analyzes the spatial geometric constraint conditions based on the degree of freedom of the configuration. Through combining the parallel manipulator and topological optimization theory, the paper puts forward the optimization model and perfects the design of 3-RPC spatial compliant parallel manipulator, and designs a new kind of 3-RPC spatial compliant parallel manipulator which is different from traditional ones. And the paper also establishes the three dimensional model of the parallel manipulator, and carries out statics simulation by using the finite element analysis ANSYS software. The simulation results show that when the compliant parallel manipulator is driven, the displacement deformation and the stress of manipulator has a reasonable distribution, the terminal motion platform can meet the micro-nanometer positioning accuracy requirements. The results of experiments have shown the validation of the theoretical analysis of the mechanism design, and proved its feasibility and effectiveness.