Abstract: The 6061-T651 plates were selected as the study subjects, and the microstructure was analyzed using metallographic microscope（OM） observation, scanning electron microscope（SEM） analysis and grain size test. Combined with the macroscopic performance of mechanical properties, the influence of final rolling temperature on the uniformity of mechanical properties of 6061 aluminum alloy plates was systematically studied. The results show that reducing the final rolling temperature from 420 ℃ to 280 ℃ can effectively reduce the difference in transverse and longitudinal mechanical properties of the plates. The difference of tensile strength of the T651 state plate is reduced from the original 21 MPa to 8MPa, and the difference of yield strength is reduced from the original 11 MPa to 5 MPa. And the mechanical properties of the two directions are improved as a whole; at the same time, the decrease of the final rolling temperature can also refine the grains, reduce the aspect ratio, and improve the processing performance of the plates.