The　dynamic　behaviors　of　double　droplets　under　an　alternating　current　(AC)　electric　field　are　investigated　by　high-speed　microscopic　experiments.　The　theoretical　mechanism　of　droplet　non-coalescence　is　revealed　based　on　the　charge　transfer　between　droplets.　The　results　show　that　two　droplets　generally　undergo　the　mode　transformation　from　coalescence　to　partial　coalescence　and　finally　to　non-coalescence　as　the　peak　strength　increases　under　the　same　electric　field　frequency.　As　the　frequency　increases,　the　number　of　droplet　rebound　dramatically　increases　and　the　duration　time　of　non-coalescence　is　significantly　prolonged.　Under　the　high-frequency　AC　electric　field,　two　droplets　experience　non-coalescence　all　the　time　due　to　the　existence　of　a　large　number　of　daughter　droplets　produced　by　the　tip　streaming,　which　is　the　basis　of　the　formation　of　stable　long　droplet　chain　in　water-in-oil　emulsion.　©　2022,　Science　Press.　All　right　reserved.