The objective of this research was to develop methods for improved the uniformity of temperature distribution within plasma surface alloying furnace by simulating the heat transfer process and numerical calculation. Results show that the structure of charging basket, hanging auxiliary cathode plates in both sides of charging basket and blackness of material influence strongly temperature distribution within the plasma surface alloying furnace. Discharge intensity of the center zone can be weakened through increasing the distance between backs both column blades in center of the furnace, which decreased the consumption of discharge power in center, depressed temperature of the center zone of the furnace. Intensity of discharge in fringe of the charging basket can be reinforced and that of discharge in center can be weakened when auxiliary cathode plates were hanged to outer flank of the charging basket, which increased boundary temperature of the system, at the same time the auxiliary cathode plate plays a heat preservation role. Decreasing the blackness of outside material of charging basket may decrease heat dissipating capacity of outside, decrease temperature difference of outside and center of the furnace and improve the uniform of temperature distribution in the furnace.