High aspect ratio gratings can be made by perpendicularly cutting in the growth direction of multilayers. X-ray exposure technique using a sectioned multilayer grating based on Talbot effect is a new type of nano patterning method. Although 300 nanometer gratings through the experiment are completed, some phenomena in the experiments cannot be satisfactorily explained and the factors influencing the nano pattern quality have not been fully understood yet. Here we use a rigorous coupled-wave theory to discuss several important factors, including grating thickness, the fraction of material thickness and multilayer period, which is the first time as far as we know for Talbot self-imaging in X-ray range. Simulation results show that the grating thickness affects both X-ray transmission efficiency and fringe contrast, while the fraction of material thickness determines the quality of fringes. And the position deviation of the best image plane in near field is related to both the thickness of the grating and the multilayer period. Moreover, the multilayer gratings with smaller periods can achieve higher resolution, indicating that the Talbot effect can be used to fabricate a more detailed structure.