Car fuel tank installing structure and car

The invention provides a car fuel tank installing structure which comprises a fuel tank support (2) connected on a frame longitudinal beam (5) and a fuel tank (1) mounted on the fuel tank support (2), wherein a support connection part (9) of the fuel tank support (2) is connected to the inner side of the frame longitudinal member (5), and the fuel tank (1) is combined to the outer side face of the frame longitudinal beam (5) in an attaching mode. The invention further provides a car provided with the car fuel tank installing structure. According to the car fuel tank installing structure, the fuel tank support is fixed on the inner side of the frame longitudinal beam so that the fuel tank is attached to the outer side of the frame longitudinal beam closely, a space occupied by an original fuel tank support is saved, volume of the fuel tank is maximized, carload driving range is ensured, and the car fuel tank installing structure is easy to manufacture, low in cost and convenient to maintain, and meets requirem