As　the　grade　of　the　transmission　line　voltage　increases,　the　electric　magnetic　field　intensity　in　the　space　around　the　transmission　line　is　getting　stronger　and　stronger.　Therefore,　the　research　on　electromagnetic　field　distribution　nearby　the　transmission　line　is　becoming　more　and　more　important.　Aiming　at　the　difficulty　of　actually　measuring　the　electric　field　intensity　in　the　upper　space　of　the　transmission　line,　a　new　test　method　is　proposed,　which　adopts　unmanned　aerial　vehicle　(UAV)　equipped　with　test　equipment　to　conduct　the　measurement.　Firstly,　the　real-time　data　of　the　electric　field　intensity　and　position　information　are　tested,　and　then　the　iOSD　system　is　used　to　compose　the　tested　data　in　real　time.　The　composed　test　data　are　stored　and　transmitted　to　the　ground　control　station,　then　the　actual　measurement　of　the　electric　field　intensity　in　the　upper　space　of　the　transmission　line　is　achieved.　The　proposed　method　was　verified　through　the　actual　test　and　analysis　of　the　Zhejiang-Fuzhou　1　000　kV　UHV　AC　transmission　line,　the　test　result　was　compared　with　the　simulation　calculation　result　using　Ansoft　software.　The　result　shows　that　the　error　between　the　simulated　value　and　measured　value　is　within　7%　when　the　distance　between　the　test　point　and　the　transmission　line　is　within　45　m,　which　demonstrates　the　effectiveness　of　the　proposed　method.　The　proposed　method　has　important　reference　value　for　the　research　of　spatial　electromagnetic　environment　of　transmission　lines.　©　2016,　Science　Press.　All　right　reserved.