The aluminum material with complex lineament which used for bus floor access cover of maintenance, its bending radius is only 70 mm. The traditional molding process is that a special injection diecasting mould is designed, then common extrusion machine, high temperature melting furnace and professional and technical workers cooperate to achieve molding. In this way, not only investment costs, production costs and energy consumption are all quite high, but also the product modifications can not keep up with the needs of products. In order to solve these problems, a small radius bending molding device for aluminum material with complex lineament was designed, and the angle was be able bended once as the needs. The arc surfaces of molding material are smooth in transition, no wrinkles, crushing and other defects.