In　order　to　study　the　aerodynamic　characteristics　of　a　Hex-rotor　micro　aerial　vehicle　(MAV)　with　different　rotor　spacing,　both　experiments　and　numerical　simulations　are　performed　in　this　paper.　First　of　all,　a　series　of　aerodynamic　parameters　to　characterize　the　hover　performance　of　the　Hex-rotor　MAV　are　analyzed　theoretically.　Secondly,　tests　on　the　Hex-rotor　MAV　with　different　rotor　spacing　ratios　(i　=0.5,　0.56,　0.63,　0.71,　0.83,　1.00)　is　presented　in　detail.　The　thrust　and　power　of　the　Hex-rotor　MAV　are　obtained　from　the　self-designed　test　platform.　In　the　meanwhile,　pressure　and　velocity　distribution　of　the　Hex-rotor　MAV　are　obtained　by　Computational　Fluid　Dynamics　(CFD)　simulation.　The　results　show　that　the　aerodynamic　performance　of　the　Hex-rotor　MAV　is　varied　with　the　rotor　spacing.　Specifically,　the　rotor　interference　is　inclined　to　improve　the　aerodynamic　performance　of　the　Hex-rotor　MAV　with　the　proper　rotor　spacing.　Owing　to　the　increase　of　rotor　spacing,　the　interactions　between　rotors　are　weakening　gradually.　In　addition,　the　uniformity　of　velocity　distribution,　the　stability　of　downwash　distribution　and　the　integrity　of　vortex　are　the　necessary　conditions　for　a　larger　thrust　of　the　Hex-rotor　MAV.　Finally,　combined　with　the　test　and　simulation　results,　it　is　also　found　that　there　is　larger　thrust　characterized　with　better　aerodynamic　performance　at　i　=　0.63,　which　is　assumed　as　the　best　rotor　arrangement　of　the　Hex-rotor　MAV.　Especially　for　Re　=　1.16　x　10(5),　the　thrust　increases　by　6.09%,　and　the　hover　efficiency　increases　by　about　9.17%　in　general.