It　is　well　known　that　there　are　multiple　sliding　surfaces　behind　inverted　T-type　retaining　walls　and　that　reflective　sliding　surfaces　may　develop　in　narrow　backfill.　Combined　with　numerical　analysis,　this　paper　establishes　a　mathematical　model　for　the　stress　rotation　trajectory　considering　multiple　sliding　surfaces.　This　paper　proposes　a　theoretical　solution　for　the　active　earth　pressure　in　narrow　backfill　on　inverted　T-type　retaining　walls　under　translation　mode　using　the　horizontal　layer　differentiation　method.　The　theoretical　solution　accurately　considers　the　redistribution　of　stresses　and　is　suitable　for　complex　working　conditions　and　various　soil　properties.　Parametric　analysis　reveals　the　effects　of　backfill　geometries,　soil　properties,　and　soil-wall　interface　friction　angles　on　earth　pressure.　A　quantitative　equation　was　presented　for　the　critical　condition　of　narrow　and　semi-infinite　backfills.　©　2021　American　Society　of　Civil　Engineers.