Abstract: The structural dimension tolerance control of key parts of aeronautical precision castings is very important to the reliability and safety of aircraft. Traditional methods use destructive cutting to measure, which is not only costly, but also unable to ensure the quality of the same batch of delivery products. In this paper, the precise industrial computerized tomography(CT) measurement method is used to measure the wall thickness of the key parts without damage, and the method is compared with the traditional measurement method, showing that the two are in good. The results show that the CT method can replace the traditional method to measure the key structure of aviation precision castings.