In order to present the defeels contained in two casting X ray DR images with diflerent grayscale window widths and windowlevels in one image, develops a kind of casting X-ray DR image fusion method based on weighted least squares filter and guided filter,One of the images is selected as the base image and the other image is selected as the detail image. The aforementioned two filters withedge-preserving property are utilized to extract the defeet information contained in the detail image. The weighted least squares filter isapplied to the base image and the output is taken as the frame, then the defects contained in the base image are separated by subtractingthe frame from the base image. The guiding fiter is used to sum the two types of defeet information with weights. Finally, the frame isused to carry the results of the weighted summation to get the fused image. Experiment results show that the obtained fused result candisplay 5 defects of two casting DR images with different grayscale window widths and window levels or 7 defeets of three casting DRimages with different grayscale window widths and window levels. The method presented in this paper can be applied to the radiographicnondestruetive testing of castings.