Abstract: CoCrFeNiTiCuMo_xV_x(x=0.5,1.0,1.5,2.0, atomic ratio) powder was mechanically alloyed in a high-energy planetary ball mill to prepare high entropy alloy powder, and influence of molybdenum and vanadium content on the phase composition, grain size and lattice strain of the alloy powder was studied by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results show that the diffraction peaks of pure metal phases disappeared, and the alloy powder with a dual-phase structure of BCC+FCC was obtained after high-energy ball milling. The content of BCC phase increased, FCC phase decreased with the increase of molybdenum and vanadium content. The alloy powder particle size was between 100-200 nm, and the particles were flat. The grain size of the alloy powder decreased and the lattice strain increased as the content of molybdenum and vanadium increased.