The invention discloses an oil tank strap locking mechanism. The oil tank strap locking mechanism comprises an oil tank bracket, an oil tank strap, a pin shaft nut, a pin shaft and a hexagon socket screw, wherein the inner side of the oil tank bracket is provided with an oil tank bracket cushion belt, the inner side of the oil tank strap is provided with an oil tank strap cushion belt, one end ofthe oil tank strap is hinged to the oil tank bracket, the other end of the oil tank strap is provided with the pin shaft, the other end of the oil tank bracket is provided with the pin shaft nut, anda screw rod of the hexagon socket screw penetrates through the pin shaft to be connected with the pin shaft nut. The invention provides the oil tank strap locking mechanism according to the use working condition of a heavy type truck, the problem of the installation stability of an oil tank is solved, the use reliability of the oil tank is increased, and the problem of oil tank shifting is effectively solved. According to the oil tank strap locking mechanism, favorable conditions are provided for improving the passing property of a vehicle, the oil tank is installed more conveniently, and thefoundation is provided for improving the use reliability of a supply system of the heavy type truck.