Terahertz radar bears the advantages of high resolution and high frame rate. It is one of the current research hotspots in the field of terahertz. Aiming at the demand for real-time ground imaging and moving target tracking, a Ground Moving Target Indication(GMTI) processing algorithm based on wide band Space-Time Adaptive Processing(STAP) is proposed. The radar imaging and Multi-channel GMTI are achieved simultaneously on the airborne terahertz radar for the first time. The effectiveness of the algorithm is verified by the experimental data of the airborne terahertz radar.