The discharge characteristics of the Hall thruster are numerically studied at different discharge voltages when the magnetic field does not change based on the particle in cell plus Monte Carlo collision methods. The distributions of electrons and Ar+ ions densities at different discharge voltages show that the change of the discharge voltage significantly influences the distribution of electrons and Ar+ ions. The electron density is relatively large when the discharge voltage is 100 V, up to 6.01 × 1018 m−3. At a discharge voltage of 400 V, the high-density region formed by electrons is significantly smaller than in other cases. The ion density rises less when reaching a steady state with increasing discharge voltage. The Ar+ ions density decreases after the discharge voltage reaches 400 V, up to 4.42 × 1018 m−3. After calculation, it was found that under a specific mass flow, the discharge voltage significantly impacts the thrust of the Hall thruster. The results have reference values for the performance testing and application of Hall thrusters.