In order to confirm the performance of detonation initiation and propulsion, the corresponding detonation initiation and propulsion experiments at different operation frequencies was carried out in this paper, based on the direct-connected test of a gasoline/air pulse detonation engine mockup. The results indicated that detonations were fully developed quickly in the PDE mockup at the operation frequency range of 0~35Hz, in which the deflagration to detonation transition (DDT) distance was about 0.9m (from the ignitor). As the operation frequency increased, the PDE average thrust increased nearly linearly while the increasing slope decreased slightly. The volume specific impulse and mixture specific impulse have the similar change trend with the operation frequency, which both increased at the increased operation frequency. The maximums of volume specific impulse and mixture specific impulse were both obtained at the operation frequency of 25Hz. Meanwhile, the fuel specific impulse increased dramatically and the specific fuel consumption decreased dramatically at the increased operation frequency of 0~25Hz. When the operation frequency exceeded 25Hz, the fuel specific impulse and specific fuel consumption changed slightly.