Automobile and fuel tank cap thereof

The invention discloses a fuel tank cap of an automobile. The fuel tank cap comprises a fixed plate (4) fixedly connected with an automobile body, a cover plate (8) for covering a fuel port of a fuel tank as well as a connecting piece for connecting the fixed plate (4) and the cover plate (8), wherein one end of the connecting piece is hinged to the fixed plate (4) through a hinge pin (2), the hinge pin (2) is parallel with the fixed plate (4), and the other end of the connecting piece is fixedly connected with the cover plate (8). The fuel tank cap is characterized in that the connecting piece is welded on the inner side plate surface of the cover plate (8), and a turned edge is arranged on the periphery of the cover plate (8). The cover plate (8) is stably connected with the connecting piece through welding, the condition of inaccurate alignment is avoided, mounting errors are reduced, and meanwhile, the strength of the fuel tank cap is enhanced by the aid of the turned edge. The invention further discloses the automobile comprising the fuel tank cap.