Porous tungsten matrix for Ba-W cathode was prepared by plasma spheroidization process combined with spark plasma sintering (SPS). The effect of plasma spheroidization process parameters on the spheroidization efficiency and properties of the W powders, microstructure of the porous W matrix sintered by SPS as well as the emission performance of the corresponding Ba-W cathode were investigated. The results show that spherical W powders with smooth surfaces and good sphericity can be obtained when the powder feed rate and carrier gas flow rate is 2.4 g/min and 4.0 L/min, respectively. The spheroidization efficiency is above 98%. The apparent density and flowability of the spherical W powders are enhanced greatly after plasma spheroidization. In contrast to the raw W powders, the structure and distribution of pores within the porous W matrix prepared by the spherical W powders are improved significantly after SPS, and the open porosity increases from 18.3% to 19.7%. The saturation pulse current density of the Ba-W cathode prepared with spherical W powders is 11.2 A/cm₂, which is higher than that of 8.7 A/cm₂ for the Ba-W cathode prepared by the raw W powders. The emission performance of Ba-W cathode can be highly improved by modifying the properties of W powders and microstructure of the porous W matrix.