The zero initial optical path difference, the integral optical path layout and the polarization interference technique are adopted to design quadruplicated polarized laser interferometer measuring system. The factors and design requirements which affect high-precision interferometer are analyzed. In order to reduce DC offset error, unequal amplitude error and non-orthogonal error, four orthogonal measuring signals are processed by a series of circuits with differential amplification and orthogonalization functions, and the two ideal orthogonal measuring signals are obtained. Beyond the VC++ environment, combined with the 200 phase subdivision, the resolution of 0.8 nm can be achieved. The measuring results are compensated and corrected according to the environmental parameters. The error sources of the measuring system are analyzed, and the quantitative values of the cosine error and abbe error are given. Compared with the British Renishaw XL-80 high-precision laser interferometer, the experimental results show that the measuring system has high stability and accuracy.