The work aims to produce more uniform film in large substrate deposited with a small target by changing the relative motion between target and traditional substrate. With the substrate rotated at a constant speed around the center shaft, the target performed rectilinear intermittent motion along the substrate radius and relevant theoretical model was set up, then numerical analysis software MATLAB was used to analyze and fit film thickness and study the effects of target-to-substrate distance, eccentric distance and target motion mode on film uniformity. When the target-to-substrate distance H=30 mm, the film thickness uniformity was affected by two important parameters: target dwell time T and moving step size d of the target at each equidistant point of radial motion. Compared with the target dwell time T=C (C is a constant), the film thickness uniformity increased significantly when target dwell time T changed in direct proportion to the target cover area on the rotating substrate. Meanwhile, the film thickness uniformity depended on moving step size of the target, the deviation between each film gradually reduced as the target moving step decreased, the results showed that the film uniformity was the best when the target moving step size d was 5 mm. The distribution of film thickness near the center of substrate could be improved by increasing the target-to-substrate distance, the relative deviation of film thickness δ was less than 0.1 with eccentric distance e=0 mm and target-to-substrate distance H≥70. By changing the traditional coating process with a stationary target and a rotary substrate, this new method is applicable to large substrate coating, which can realize higher uniformity and fewer differences between each layer of the film by adjusting moving step size and dwell time of the target during the process of film deposition. All the conclusions are of guiding significance to actual industrial production.