We report a wavelength-tunable harmonically mode-locking dissipative soliton fiber laser based on a high-speed intensity modulator with a simple all-polarization-maintaining (all-PM) cavity. The center wavelength can be precisely tuned from 1029.35 to 1079.25nm by tuning only the frequency of the pulse pattern generator (PPG), and the linear tuning accuracy of the wavelength can reach 0.0093nm/kHz. The degree of polarization can reach 98.969%. The FWHM of the pulse is measured to be 30.1ps, and the intracavity pulse energy after the gain fiber can reach 5.41nJ. All orders of the harmonic mode-locking repetition rate are tuned from ∼33.346 to ∼366.806 MHz through adjustment of the data length and frequency of PPG.