Micro　light-emitting　diode(μLED)　is　one　of　the　most　cutting-edge　display　technologies　in　the　world.　It　generally　refers　to　the　LED　array　with　a　single　mesa　size　less　than　50　microns.　Compared　with　liquid　crystal　display(LCD)　and　organic　light　emitting　diode(OLED)　display,　μLED　display　technology　has　its　unique　advantages:　long　lifetime,　short　response　time,　and　high　brightness.　Most　importantly,　it　enables　the　realization　of　highly　integrated　displays,　which　includes　both　high-PPI　displays　with　much　higher　pixel　densities　than　conventional　display　technologies,　and　highly　integrated　semiconductor　information　displays(HISID)　that　have　been　proposed　first　by　us　and　contain　certain　non-display　components.　In　many　figures　of　merit　of　display　technology,　μLEDs　perform　excellently.　However,　as　μLEDs　greatly　reduce　the　size　of　conventional　LED　devices　and　typically　have　an　increased　device　density,　many　new　technical　and　physical　challenges　have　arisen,　such　as　mass　transfer　technology,　full-color　display,　etc.　Therefore,　μLEDs　have　not　yet　achieved　any　real　industrialization.　In　this　paper,　the　highly　integrated　μLED　display　technology　research　and　progress　are　described　systematically.　First　of　all,　the　basic　principle　and　structure　of　μLEDs　are　introduced,　followed　by　the　classification　and　review　of　the　key　technologies.　Finally,　the　development　trends　and　application　prospects　of　the　μLED　display　technology　are　analyzed.　©　2020,　Science　Press.　All　right　reserved.