High-quality nano-tungsten powder is the prerequisite for the preparation of high-performance nanocrystalline tungsten alloys and cemented carbides. The tungsten powder prepared by hydrogen reduction producesWO2(OH)2, which leads to the growth of tungsten powder grains. The carbothermal reduction method can effectively avoid this problem. This study focuses on the influence of carbothermal reduction temperature, atmosphere, time and dynamic/static process on the phase structure and particle size of the product. The results showed that the purity of the product in vacuum atmosphere was higher than that in argon atmosphere. With the increase of reduction temperature, the product changes from high valence tungsten oxide to low valence tungsten oxide and finally to pure tungsten. When the holding time is 1h, the average particle size of tungsten powder increases from 67 nm to 118 nm with the increase of reduction temperature from 1000 ℃ to 1100℃.When the reduction temperature is 1000 ℃, the average particle size of tungsten powder increases from 67 nm to 93 nm with the increase of holding time from 1h to 3h. The dynamic reduction is also due to the more uniform contact of the reactants and the higher purity of the product obtained by the more complete reaction than the static reduction. Nano-tungsten powder with an average particle size of 67 nm was prepared under the optimized vacuum dynamic carbothermal reduction at 1000 ℃ for 1 h.