In this paper,the diffraction-enhanced imaging method was applied to the non-destructive testing of computed-tomography. With this technique,the 2-D cross-section image of the self-designed sample was reconstructed. The reconstructed images depict clearly the inner structures of the sample. By comparing these images with the reconstructed image obtained by the absorption imaging computedtomography,the result indicates that the technique of diffraction-enhanced computed-tomography can acquire better boundary among these elements that their absorption coefficients are very close in the object.