The interferometer adopted polarized light measurement and polarized light receiver is presented. The transform of the polarized light is analyzed in detail, which can help the design of polarized interferometer and dual-frequency interferometer. The repeatitiveness test indicates that the interferometer's measurement accuracy of repeatitiveness is within 30 nm. The result shows that the interferometer is reliable.If the effects of the environmental factors on the measurement accuracy and the compensation for the enviromental changes are studied, the measurement accuracy will be nanometer level.