The　installation　of　heaters　to　raise　the　temperature　inside　the　switchgear　cabinet　is　one　of　the　most　common　methods　to　prevent　condensation　of　insulation　parts　inside　the　switchgear　cabinet.　In　view　of　such　problem　as　unreasonable　installation　position　of　existing　heaters　and　aging　of　insulation　parts　due　to　excessive　heating，a　kind　of　layout　strategy　of　heater　for　12　kV　switchgear　cabinet　based　on　effective　heating　space　is　proposed.　Firstly，according　to　the　generation　mechanism　of　condensation，the　corresponding　relationship　between　dew　point　and　room　temperature　is　set　up，and　the　effective　heating　space　of　single　heater　with　different　types，power　and　installation　methods　is　tested　and　studied.　Then，the　combination　mode　of　different　types　of　heaters　is　designed　in　combination　with　the　effective　heating　space　of　various　types　of　heaters.　The　effective　temperature　rise　test　is　carried　out　in　12　kV　switchgear　cabinet　to　determine　the　combination　scheme　of　the　heater　corresponding　to　the　target　temperature　rise.　Finally，as　for　the　southeast　coastal　provinces　in　China，the　meteorological　monitoring　data　of　environmental　temperature　and　humidity　in　each　district　and　county　in　2019　is　used.　The　defined　temperature　rise　combination　scheme　is　classified　as　per　region，and　a　regional　differential　layout　strategy　of　heater　of　12　kV　switchgear　cabinet　is　achieved.　The　results　show　that　the　layout　of　the　heater　defined　by　this　method　has　better　heating　effect　and　more　uniform　temperature　rise　distribution　than　the　blind　layout.　In　addition，the　regional　layout　strategy　can，to　a　large　extent，increase　the　applicability　of　each　scheme，which　has　a　certain　practical　reference.　©　2023　Xi＇an　High　Voltage　Apparatus　Research　Institute.　All　rights　reserved.