The utility model discloses a wheel nut, including a nut body which the outside surface comprises of multiple identical arc surfaces. The arc surface is protruding outward, and the radius of the arc surface is larger than the circumscribed radius of the outside surface of the nut body. The utility model designs the existing square surface of the outer hexagon feature of the wheel nut as an arc surface, which the contact area between the wheel nut and the sleeve and the loading area of the wheel nut can be increased, and then the deformation and looseness of the wheel nut can be avoided effectively, and therefore the service life of the wheel nut can be improved.