The primary issue regarding the plasma synthetic jet actuator(PSJA) is its performance attenuation at high frequencies. To solve this issue, a self-supplementing, dual-cavity, plasma synthetic jet actuator(SD-PSJA) is designed, and the static properties of the SD-PSJA are investigated through experiments and numerical simulations. The pressure measurement shows that the SD-PSJA has two saturation frequencies(1200 Hz and 2100 Hz), and the experimental results show that both the saturation frequencies decrease as the volume of the bottom cavity of the SD-PSJA increases. As the size of the supplement hole increases, the first saturation frequency increases continuously, while the second saturation frequency shows a trend of first decreasing and then increasing. Numerical simulations show that the working process of the SD-PSJA is similar to that of the PSJA, but the volume of the cavity in the SD-PSJA is smaller than that of the PSJA; the SD-PSJA can supplement air to the top cavity through two holes, thus reducing the refresh time and effectively improving the jet intensity of the actuator at high frequencies.