This　paper　introduces　the　classification　of　indoor　positioning　technology,　and　elaborates　the　principles　of　three　mainstream　indoor　positioning　technologies　based　on　external　source,　natural　source　and　multi-source　fusion　and　their　development　respectively.　By　analyzing　the　problems　of　existing　indoor　positioning　technologies,　it　summarizes　the　difficulties　and　future　trends　of　the　current　development　of　indoor　positioning　technologies　at　home　and　abroad.　The　comprehensive　study　shows　that　exploring　combined　positioning　techniques　and　better　positioning　algorithms,　and　combining　them　with　machine　learning　(including　deep　learning)　to　further　improve　indoor　positioning　accuracy,　establishing　a　standard　system　and　performance　evaluation　system　for　indoor　positioning　techniques,　and　focusing　on　user　privacy　are　the　main　future　development　directions　of　indoor　positioning　techniques.　©　2024　Copyright　held　by　the　owner/author(s).