X-ray grating imaging technology can use traditional X-ray machine to get the attenuation, phase contrast and dark information of the object to be tested in one image. The basic principle and system structure of the X-ray grating imaging are introduced. And then, the respective characteristics, mutual influence and relevant features of three kinds of information of the same scence are analyzed, which are obtained by the same sensor in the same space and time. The attenuation, phase contrast and dark information are used to fuse based on the wavelet transform. The simulation results of the original Pfeiffer′s experimental data show that, reasonable image fusion technology can realize a one-time high resolution imaging detection in large dynamic range, including various light and heavy elements.