HTS flux pump is a contactless charging method for a superconducting magnet, which can reduce the cryogenic losses associated with current leads. Rotating type flux pump is a simple and practical flux pump, which has great application in charging HTS magnets. For the rotating flux pump, the design of rotor has great impact on the performance of flux pump. In this study, we will change the rotor design of the rotating type flux pump. Different design will be compared and analysed. Based on the study, we will investigate the effective methods to improve the performance of HTS flux pump.