Abstract: In order to increase the digital radiography(DR) image information of the object with uneven thickness, a fusion method based on wavelet transform on two DR images of different Xray energy was introduced. Firstly, the input images were decomposed by wavelet transform. Secondly, the weighted average method was used to choose the weight coefficients of low frequency subimage. And the eight directional masks were used to detect the local gradients. On the basis of the local gradients the fused high frequency coefficients were obtained. Finally, through inverse wavelet transform the output image could be obtained. In addition, entropy and spatial frequency were used to evaluate the fused images. Experiments showed that this method was effective.