Real-time　hybrid　simulation　(RTHS)　is　a　novel　testing　method　that　combines　numerical　simulation　and　physical　testing　to　evaluate　the　dynamic　performance　of　engineering　structures　in　large　specimens　using　existing　experimental　facilities,　thus　eliminating　the　scaled　effect.　In　recent　years,　studies　on　RTHS　have　expanded　beyond　traditional　engineering　structures,　such　as　wind　turbines,　automobiles,　and　ocean　structures.　Thus　far,　the　dimensions　of　physical　substructures　in　RTHS　are　still　relatively　small,　limited　by　the　accuracy　of　system　control　for　physical　systems　and　the　real-time　calculation　efficiency　of　numerical　simulations.　This　study　summarizes　the　achievements　of　real-time　numerical　simulations　for　RTHS,　including　the　dimensions　of　the　physical　specimen,　strategy　of　numerical　simulation,　and　integral　algorithms　of　RTHS.　Meanwhile,　two　theoretically　feasible　methods　based　on　parallel　computing　and　surrogate　models　are　discussed,　which　may　be　the　development　trends　needed　to　improve　the　efficiency　and　accuracy　of　numerical　solutions　in　real-time　and　enlarge　the　application　scope　of　RTHS.　©　2022　Tianjin　University　and　John　Wiley　&　Sons　Australia,　Ltd.