Wheel mould bottom mould deformation-preventing device

The utility model discloses a wheel mould bottom mould deformation-preventing device which comprises at least two pre-stress rings. At least one pre-stress ring is arranged on a back cavity of a bottom mould, and the distance from the pre-stress ring to a center hole is one third to a half of the radius of the bottom mould. Another pre-stress ring is arranged at the outmost end of the bottom mould and is in interference fit with the bottom mould. The pre-stress ring arranged on the back cavity of the bottom mould is embedded into the wheel mould bottom mould. The wheel mould bottom mould deformation-preventing device can solve the problem of thermal deformation of the wheel mould bottom mould, and prolongs service life of a mould.