An experimental investgation on the plasma temperature after the precursor powder injection can provide a reference for the process optimization in plasma spheroidization. The effect of tungsten powder injection on the intensity of emission spectrum and plasma temperature were investigated at different position and RF power with a single factor method, and the tungsten powder with the particle size of D50=20±5μm was spheroidization treatment. The results show that the emission intensity and temperature of plasma jets was both decreased after tungsten powder injection. The effect of plasma temperature was weakened with the increase of RF power, and the spheroidization and satellite ratio were about 95% and 21% when P=56kW, respectively. The flow ability and density of powder were significantly improved after plasma spheroidization.