Abstract: In order to study the influence of configuration and operating parameters of open-end swirl injector on its dynamics,a group of swirl injector models were designed based on the physical dimension of RD120 pre-burner kerosene injector.The calculation result shows that,the amplitude of flow rate of open-end swirl injector declines with the increase of fluctuation frequency,and the delay phase increases with fluctuation frequency.The bigger pressure-drop means wider amplitude of flow and lower delay phase.The open-end swirl injector with larger geometrical characteristic A and length/diameter ratio can dampen more flow rate fluctuations.Since the delay phase increase linearly with the length of vortex chamber,the axial spacing of tangential inlet could be adjusted to filter the fluctuation of a certain frequency.