The 2DEG samples of GaAs/AlxGa1-xAs was prepared by adopting MBE. In the process of sample preparation, by changing the constituent content of Al and the thickness of the isolation layer and comparing the body doping with the delta doping, we perform the Hall test under the condition of 300 K the migration rate of room temperature is 7.205×103 cm2/Vs and the carrier concentration is the open groove structure of 2DEG of GaAs/AlxGa1-xAs, which is 1.787×1012/cm3. Besides, the software of Mathematica is adopted to respectively calculate the THz response rates of GaAs-based HEMT structures with different channel widths under the temperature of 300 K and 77 K, which have provided the references for the research and preparation of HEMT THz detectors.