Porous　media　play　important　roles　in　a　wide　range　of　scientific　and　engineering　problems.　Recently,　with　their　increasing　application　in　energy　conversion　and　storage　devices,　such　as　fuel　cells,　batteries　and　supercapacitors,　it　has　been　realized　that　transport　processes　and　reactions　occurring　in　the　pores　and　at　the　interfaces　of　different　constituents　significantly　affect　the　performance　of　the　porous　media,　yet　these　pore-scale　transport　phenomena　are　not　well　described　or　even　neglected　in　the　conventional　numerical　models　based　on　the　representative　element　volume　(REV).　Pore-scale　modeling　is　an　efficient　tool　for　the　simulation　of　pore-scale　transport　and　reactions　in　porous　media　because　of　its　ability　to　accurately　characterize　these　processes　and　to　provide　the　distribution　details　of　important　variables　which　are　challenging　for　current　experimental　techniques　to　provide　either　due　to　lack　of　in-situ　measurement　capability　or　due　to　the　limited　spatial　and　temporal　resolution.　In　the　present　review,　the　advances　and　challenges　of　the　state-of-the-art　pore-scale　modeling　are　summarized.　The　practical　applications　of　pore-scale　modeling　in　the　fields　of　geoscience,　polymer　exchange　membrane　fuel　cells　(PEMFC)　and　solid　oxide　fuel　cells　(SOFC)　are　discussed.　Notable　results　from　the　pore-scale　modeling　are　presented,　and　the　challenges　facing　the　pore-scale　model　development　are　discussed.　This　in-depth　review　is　intended　to　give　a　well-rounded　introduction　of　critical　aspects　on　which　the　pore-scale　modeling　can　shed　light　in　the　development　of　relevant　scientific　and　engineering　systems.　©　2021　Elsevier　Ltd