An integrated single-frequency laser interferometer is researched based on polarized light theory. A four-subdivision configuration of the interferometer is achieved by using method of polarization states conversion which can improve the precision of the system. A four-orthogonal detection system is built up and the passive polarization modulation is accomplished which can expand the range of measurement. The integration of the interferometer is achieved by integration optical path. The vibration measurement experiments of the laser interferometer are carried out under laboratory condition. The error of the static displacement measurement is less than 0.3 nm, and the resolution of the vibration measurement reached is up to 10 pm/Hz1/2. The results show that the integrated interferometer has advantages of high accuracy, good stability, large measurement range and resistance to environment effect. Therefore, the integrated interferometer can be widely used in various fields of nano measurement.