Compliant micro-positioning mechanisms play an important role in precise positioning and displacement technology. In this paper, a new kind of compliant mechanism based on Roberts mechanisms is proposed for the mechanism design of a novel parallel-kinematic XY micro-positioning stage. Pseudo-rigid-body model (PRBM) is developed to establish the quantitative models, which show that the XY stage has a work range larger than 14 mm in each axis with a relative compact dimension. Moreover, the stage performances are verified by conducting finite-element analysis (FEA) simulation. Results not only validate the analytical models, but also demonstrate the nice decoupling performance of the designed XY stage. The FEA simulation results show that the parasitic motion in the nonworking direction was less than 0.1% of the motion stroke. It indicates that the proposed design meets the requirements of a large stroke, high precision linear guiding mechanism. A prototype XY stage is fabricated for further investigation.