A preparing method of an aluminum alloy base material for an electronic product shell comprises the steps that burdening is carried out according to the weight ratio of various alloy components, pure aluminum, pure zinc, AlCu50 alloy and AlZr5 alloy are put into a smelting furnace to be smelted, and the smelting temperature is 720-770 DEG C; then pure magnesium is input, and the temperature is controlled between 750 DEG C and 770 DEG C during inputting; the mixture is transferred into a holding furnace at the temperature of 710-730 DEG C to be subjected to heat preservation, the holding furnace is inflated with chlorine and argon for refining for 1-2 h, standing is conducted for 1-2 h, the holding furnace is inflated with chlorine and argon again for refining for 1-2 h, and standing is conducted for 1-2 h; the mixture is transferred into an online degassing and deslagging device, during online degassing, the volume proportion of chlorine is 2-5%, and a grain refiner is added online; and finally, filtering and deslagging are conducted, a cast ingot with the uniform structure is cast, and after the cast ingot is subjected to homogenization, preheating and rolling and reaches the target thickness, a product is obtained through annealing via a continuous annealing device. According to the preparing method, the actual production situation is combined, aluminum alloy good in color and luster, low in black line reject ratio and free of bank marks after being subjected to anodic oxidation is developed, and sheet strips uniform in performance can be stably produced on a large scale.