Method and system for determining size of allowable crack on surface of cast turbine disc

The invention relates to the technical field of aero-engine damage tolerance design, and discloses a method and system for determining the size of an allowable crack on the surface of a cast turbine disc. Obtaining a first maximum temperature of a wheel disc examination area and a maximum first principal stress of the examination area; then, a crack is inserted in the maximum first principal stress position of the wheel disc examination area, so that the stress intensity factor of the crack in the maximum first principal stress position of the examination area is obtained, and the wheel disc allowable maximum stress intensity factor is obtained according to the incidence relation between the stress intensity factor of the crack in the maximum first principal stress position of the examination area and the wheel disc allowable maximum stress intensity factor; accurate determination of the allowable crack size on the surface of the cast turbine disc is achieved, certain engineering use value is achieved, and th