Abstract: Plasma synthetic jet technique not only has the advantages of synthetic jet, such as zero-net-mass-flux and needlessness for additional gas source, but also has the advantages of plasma, such as high working frequency and the ability of rapid response, which gives itself the great potential for application. The direction of the jet exit of traditional actuator has a definite angle with the horizontal direction. So the dynamic pressure is impacted by the direction of the jet exit of the actuator. The actuator was designed by the model of Narayanaswamy et al, in order to enhance the capability of horizontal momentum injection. Schlieren and the testing technique of electric parameters were used to test the operating characteristics of the horizontal momentum injection actuator. This paper mainly focused on the characteristic of flow-field and dynamic pres-sure. What's more, the experiment of dynamic pressure was conducted to research the flow control capability. The experimental results show that the initial velocities of jet front and blast wave reach about 220m/s and 477m/s, respectively. Moreover, the deposited energy decreases with the operating frequency, resulting in lower exit dynamic pressure.