The invention belongs to the technical field of machinery, and provides an automobile external water slot aluminum bright strip end flanging former which comprises a base, a left trimming component, a right trimming component, an upper flanging die component, a lower flanging die component, a side thrust supporting component and a flanging positioning component. The left trimming component, the right trimming component, the lower flanging die component, the side thrust supporting component and the flanging positioning component are arranged on the base, and the upper flanging die component is positioned at the upper end of the base and is vertically opposite to the lower flanging die component. Compared with the prior art, the automobile external water slot aluminum bright strip end flanging former has the advantages that a product is horizontally placed and is simple and convenient to operate, the product can be automatically flanged and trimmed through driving control of an oil cylinder and a cylinder only by clamping the product on the flanging former, automation degree is high, production efficiency is greatly improved, the product can be formed only by one-step clamping, product quality is stable and is correspondingly improved, two ends of a bright strip can be simultaneously formed, working hours are shortened, and cost is saved.