A novel method for measuring Doppler Frequency Shift （DFS） based on dispersion-tuned Actively Mode-Locked Fiber Laser （AMLFL） technique is proposed and successfully demonstrated. The measurement principle is based on the fact that the output wavelength of the actively mode-locked fiber laser is linearly related to the Radio Frequency （RF） applied to the modulator in the laser cavity with large dispersion， so that the input frequency and further the DFS can be obtained by measuring the output wavelength of the AMLFL. Influences of system parameters such as the laser cavity length， dispersion， and mode-locked orders on the system performance are theoretically analyzed. Under the guidance of the simulation and for different application condition， two experiments are designed respectively based on long Dispersion-compensated Fiber （DCF） and Linearly Chirped Fiber Bragg Grating （LC-FBG） to provide large dispersion， and DFS measurements are conducted when the carrier frequencies are respectively 12.2 MHz， 265 MHz， 682 MHz and 1.118 7 GHz. The technique has advantages of simple configuration and flexible design， and may have potential application in measurement of Doppler frequency shift.