A fiber laser with a wavelength of 1064 nm was used for laser cleaning of the rusted layer on Q345 steel surface, and the effect of laser scanning speed on the cleaning quality was studied. The results show that when the scanning speed is smaller than 1000 mm·s -1, the laser significantly damages the substrate; when the scanning speed reaches 5000 mm·s -1, some rust remains on the material''s surface; when the scanning speed is 3000 mm·s -1, the cleaning effect is better and the substrate will not be damaged. As the speed increases from 1000 mm·s -1 to 6000 mm·s -1, the Fe content on the Q345 steel surface after cleaning shows a tendency of increasing firstly and then decreasing, while the O content decreases firstly and then increases. When the scanning speed is 3000 mm·s -1, the Fe element content on the Q345 steel surface reaches a peak of about 90%, the O element content reaches a valley value of about 7%, the compounds of Fe and O are also less and the surface roughness (Ra≈6.9 μm) of the steel is also low. Good laser cleaning effect can be obtained by adjusting the scanning speed appropriately. After laser cleaning, the electrochemical corrosion performance of Q345 steel surface can be enhanced.