This　paper　focuses　on　theoretical　analytical　models　to　calculate　the　limit　support　pressure　and　vertical　earth　pressure　on　the　cutting　face　for　tunnels.　The　failure　zone　is　divided　into　two　parts:　a　sliding　failure　zone　and　an　upper　loosen　zone,　and　the　limit　support　pressure　calculation　equation　is　derived.　To　verify　the　rationality　of　the　theoretical　model,　it　was　compared　with　the　existing　theory,　numerical　simulation,　and　centrifugal　test,　and　then　the　parameter　analysis　was　carried　out.　The　results　show　that　the　results　of　this　paper　agree　well　with　the　existing　theory,　numerical　simulation,　and　centrifugal　test.　The　inclination　angle　of　the　proposed　mechanism　is　determined　based　on　the　results　of　the　existing　centrifuge　test,　and　the　recommended　inclination　angle　is　between　52°　+　φ/2　and　54°　+　φ/2.　The　method　is　proven　to　be　safe　and　accurate.　It　can　provide　a　theoretical　basis　for　similar　projects.　©　2023　Tongji　University