Herein, a 2024 aluminum alloy coated with a 150 μm epoxy primer was cleaned using a nanosecond pulsed laser with different pulse frequencies. Moreover, the surface morphology, surface roughness, cleaning thickness, and cleaning mechanism were analyzed. Experimental results show that the surface roughness (R_a) was slightly affected by the pulse frequency and was about 3 μm. Furthermore, the cleaning depth was calculated under different pulse frequencies; the results show that the cleaning depth reached about 130 μm at a pulse frequency of 10 kHz. The effect of the laser frequency on the ablative amount and thermal stress was studied during laser cleaning via numerical simulations. Numerical simulation results show that the ablative amount decreased with the increase in the frequency and the maximum decrease in ablative amount was >9% when the pulse frequency was 5?25 kHz. The trigger threshold of the peeling mechanism was approximately 1.64 J/cm² based on the linear fitting calculation of the maximum thermal stress and pulse energy density. When the pulse energy density was greater than 1.64 J/cm², it was difficult to accumulate heat as the frequency increased, which weakened the ablation mechanism. However, as the frequency increased, the peeling mechanism was enhanced; thus, a good cleaning effect could be obtained.