In order to solve the mismatch and the high standing wave in antenna are influenced by the plasma sheath in the surface of high speed aircraft, an adaptive antenna matching design is proposed. The mismatch antenna with plasma sheath effect was realtime measured by the microstrip line directional coupler, the Pi type impedance matching network embedded in antenna was performed according to the impedance value of the mismatch antenna, eventual matching of antenna was achieved. The design was not used the inductive component in the Pi type matching network, but instead of a 1/4 wavelength transmission line with low loss varactor. The entire system was designed in S band frequency, the insertion loss of entire system was 0.63 dB by experimental measured. The experimental results show that the system can reconfigure the standing wave of the mismatch antenna from 10 to 1.5.