In order to prepare high-quality mercury cadmium telluride (HgCdTe) materials with high reliability and controllable doping concentration, the properties of HgCdTe materials after As doping need to be studied. The As doping technology of silicon-based HgCdTe by molecular beam epitaxy (MBE) is reported. Using As cracking source as As doping source, high-quality HgCdTe materials are prepared, in which the As doping concentration can reach 8×10¹⁸ cm^-3. The study found that As doping is very sensitive to material growth parameters such as growth temperature, As beam current, and material composition. By improving the growth temperature control and substrate heating method, the uniform distribution of As concentration in the horizontal and vertical directions of the material can be achieved. As activation annealing is carried out by a two-step annealing method. When the As concentration is lower than 3×10¹⁷ cm^-3, the activation rate tends to 100%; with the increase of As doping concentration, the activation rate shows a downward trend.