Method of off-axis rotated scan is studied in order to improve the thickness uniformity of the film by pulse laser deposition (PLD). Based on the principle and spatial distribution of plasma, radial distribution formula of film thickness is formed. Effects on uniformity of film deposited by method of off-axis rotated scan are simulated numerically. The simulated results show that optimize of d (distance between sputtering dot and foundation) and r (interval between particle center and foundation center ) are primary means for improving the uniformity of film. In addition, influence of electromotor rotate speed, working time and laser repetition frequency is considered. Simulated with optimal parameters, maximum radius of film diameter over 40 mm is obtained when 95% uniformity is required.