The utility model discloses an aluminum magnesium alloy D-shaped fuel tank and belongs to the field of vehicle parts. The aluminum magnesium alloy D-shaped fuel tank comprises a D-shaped cylinder body, D-shaped end covers, a D-shaped clapboard, a fuel filling opening, a fuel discharging plug, a liquid level flow rate sensor and an air hole, wherein the D-shaped end covers are arranged on the two sides of the D-shaped cylinder body; the D-shaped clapboard is arranged in the D-shaped cylinder body; the fuel filling opening is formed in the D-shaped cylinder body; the air hole is adjacent to the liquid level flow rate sensor. Due to the fact that the aluminum magnesium alloy D-shaped fuel tank provided by the utility model is of a D-shaped structure, the aluminum magnesium alloy D-shaped fuel tank is suitable for being integrally mounted on a vehicle frame, and the travelling smoothness of a commercial vehicle is improved; due to the fact that the arc D-shaped clapboard with a hole is arranged and the two sides of the D-shaped clapboard are inward, the whole structural strength of the fuel tank is improved; when a vehicle is driven on a bumpy road surface, the fuel tank is not easily deformed, and is good in stability; the problem that the interior of the fuel tank is corroded is solved; the service life is prolonged; the aluminum magnesium alloy D-shaped fuel tank has the advantages of high strength, corrosion resistance, no rusting, difficulty in deformation and the like.