The microstructures and modification performance on 4032 aluminum alloy of the Al-10Sr master alloy wire prepared from“direct reaction-hot extrusion”and the trapezoidal block from“direct reaction”were systemically studied by using optical metallurgical microscope, XRD and SEM. It was found that the preparation processes exhibited a significant effect on the microstructures of the Al-10Sr, which thereby influenced its modification performance. It has been found that when the Al-10Sr alloy wire was used, a desirable modification was obtained after 2 min and reached to the best performance at 60 min, and the optimum Sr addition amount was 0.04-0.06 wt%, and the good modification performance was kept even after 300 min. However, when the Al-10Sr alloy trapezoidal block was used, a desirable modification was started after 30 min and reached to the best performance as long as 120 min, and the optimum Sr addition amount was 0.06-0.08 wt%, and the effective modification period was only 180 min. Therefore, comparing with the Al-10Sr alloy trapezoidal block, the Al-10Sr alloy wire had better modification efficiency, which not only reduced the Sr addition amount of about 30%, but also greatly decreased the incubation time and improved the ability of anti-fading.