The　influence　of　cooling　rate　on　the　microstructure　of　Al0.6CoCrFeNi　high　entropy　alloy　(HEA)　powders　was　investigated.　The　spherical　HEA　powders　(D50　approximate　to　78.65　mu　m)　were　prepared　by　high　pressure　gas　atomization.　The　different　cooling　rates　were　achieved　by　adjusting　the　powder　diameter.　Based　on　the　solidification　model,　the　relationship　between　the　cooling　rate　and　the　powder　diameter　was　developed.　The　FCC　phase　gradually　disappears　as　particle　size　decreases.　Further　analysis　reveals　that　the　phase　structure　gradually　changes　from　FCC+BCC　dual-phase　to　a　single　BCC　phase　with　the　increase　of　the　cooling　rate.　The　microstructure　evolves　from　planar　crystal　to　equiaxed　grain　with　the　cooling　rate　increasing　from　3.19x10(4)　to　1.11x10(6)　K/s.