Phase-modulated Doppler lidar could benefit from both direct detection Doppler lidar and coherent detection Doppler lidar. However, owing to the lack of dynamic range of its own frequency-shift measurement, its practical application is limited. In this paper, a star map method to measure the signal optical frequency shift was proposed, which used the changing of phase-modulation discriminate parameters in the two- or three-dimensional coordinate system. Furthermore, the models of its measurement sensitivity and error were derived. The proposed method could not only effectively maintain the advantages of the conventional method but also greatly improve the dynamic range of the frequency-shift measurement.Theoretical research showed that the method could increase the measurement dynamic range by approximately nine times. The correctness and effectiveness of the proposed method were experimetnally proven by measuring actual targets.