Silicon Hall-effect sensors have been widely used in industry and research fields due to their straightforward fabrica-tion process and CMOS compatibility.However,as their material property limitations,technicians usually implement complex CMOS circuits to improve the sensors'performance including temperature drift and offset compensation for fitting tough situ-ation,but it is no doubt that it increases the design complexity and the sensor area.Gallium arsenide(GaAs)is a superior materi-al of Hall-effect device because of its large mobility and stable temperature characteristics.Concerning there is no specified mod-elling of GaAs Hall-effect device,this paper investigated its modelling by using finite element method(FEM)software Silvaco TCAD·to help and guide GaAs Hall-effect device fabrication.The modeled sensor has been fabricated and its experimental res-ults are in agreement with the simulation results.Comparing to our previous silicon Hall-effect sensor,the GaAs Hall-effect sensor demonstrates potential and reliable benchmark for the future Hall magnetic sensor developments.