As the resolution, accuracy and other parameters of the phase-shifting unit in a phase-shifting lateral shearing interferometer will directly affect the test accuracy of wavefront aberration for a lithograph objective, a phase-shifting component with macro and micro compound motion modes was designed based on the principle of phase-shifting test for wavefront aberration. It could achieve a phase-shifting resolution of 3 nm in a 25 mm travel range. Moreover, the mathematical relation of initial parameters was analyzed for the micro unit with a flexure hinge composited four linkage structure. The stiffness and weak interfacial stress of the flexure hinge were calculated, and a design example was given. The finite element analysis method was used to simulate the relation between phase-shifting value and the output of piezoelectric ceramic (PZT) and to analyze the phase-shifting accuracy. The results show that the PZT can actuate one-dimensional phase-shifting motion in 0.1 mm-1 nm within its output range, and the theoretical accuracy is better than 3.5 nm. The open-loop calibration test shows that the actual accuracy of micro-motion unit in the phase-shifting component is better than 5 nm.