Abstract: The paper aimed to evaluate whether the residual ceramic core in a hollow blade could be found through analyzing the residual ceramic cores image of radiographic contrast. Moreover, it analyzed some important influence factors of imaging contrast which could be educed from the formula of images radiographic contrast. Forthermore, some values under certain energy were also calculated through the formula. In addition, through comparing the results of experiment with the calculating results according to the formula, it was shown that the image contrast could be increased efficiently by improving the grads of film and the scattering ratio of X-ray. Finally, the minimum ceramic cores thickness which could be tested on the material of blades was also acquired.