At present,laser polarization state of Nd∶YAG laser feedback interferometer is easy to change.Compared with Nd∶YAG crystal,a single longitudinal mode linearly polarized light of Nd∶YVO4 crystal is more stable,and the center frequency of relaxation oscillation is higher,thus velocity measurement accuracy increases with the increase of shift frequency.Nd∶YVO4 laser feedback interferometer prototype is designed and manufactured,and a digital phase meter with external trigger function is used.After the optical power stability experiment and comparative experiment,the indexes of the laser feedback interferometer are obtained.The laser power fluctuation is 1.89% within 3 h,linearity is 7.0625×10-6 within the 400 mm measuring range and standard deviation is 0.936 μm.