A Be-window-type X-ray zooming tube is an X-ray digital imaging system whose magnification factor of X-ray images can be easily varied from 10 to 200, and whose spatial resolution is less than 0.5 µm. This zooming tube was used as an imaging detector in double-crystal X-ray topography to obtain high-resolution images of dislocations in a silicon crystal. X-ray interference images of about 5 µm were observed even though optimal performance of the X-ray zooming tube could not be achieved. The results indicate that the X-ray zooming tube might make a good detector for X-ray topography with minor improvements in its stage structure.