Abstract: A novel synthesis route for Ta10W refractory alloy nanopowders was designed to overcome the limitations of conventional methods in achieving compositional homogeneity. Using ammonium paratungstate (APT) and tantalum pentachloride (TaCl₅) as the raw materials, the Ta–W composite oxide was first prepared through chemical co-precipitation followed by calcination at 700 ℃ for 10 h. The resulting oxide featured nanoscale structure with uniformly distributed Ta and W elements (9.8% mass fraction of W), serving as the essential precursor. The target alloy nanopowders were then synthesized by molten salt-assisted magnesiothermic reduction (NaCl) at 1000 ℃ for 5 h, with the subsequent acid washing. The successful formation of single-phase Ta10W solid solution were confirmed by X-ray diffraction and transmission electron microscopy (TEM), having the calculated lattice constant of 0.334 nm. The highly homogeneous distribution of Ta and W without detectable segregation was further demonstrated by TEM-energy disperse spectroscopy (EDS). In the results, the powder particles exhibit the ellipsoidal morphology with sizes broadly distributed between 2～253 nm, more than half of the particles are below 80 nm. Control experiments highlight the importance of both the molten salt medium and the sufficient reaction time. The integrated approach combining chemical precipitation, calcination, and molten salt magnesiothermic reduction effectively resolves the co-precipitation challenges associated with Ta and W salts, enabling the successful preparation of homogeneous, high-purity, and well-dispersed Ta10W alloy nanopowders.