At　present,　the　Internet　of　Things　(IoT)　is　applied　to　all　aspects　of　people＇s　lives.　The　traditional　cloud-based　Internet　of　Things　has　been　unable　to　support　the　development　needs　of　the　Internet　of　Things　at　this　stage.　The　emergence　of　edge　computing　provides　new　opportunities　for　the　development　of　the　Internet　of　Things,　but　also　brings　new　security　threats.In　view　of　the　security　requirements　for　nodes　in　the　IoT　edge　computing　scenario,　this　paper　proposes　a　comprehensive　trust　evaluation　model　for　terminal　nodes　based　on　improved　Bayesian　theory.　Aiming　at　the　time-effectiveness　of　trust,　a　trust　decay　strategy　is　designed,　and　a　direct　trust　evaluation　of　IoT　terminals　is　carried　out　based　on　improved　Bayesian　theory.At　the　same　time,　aiming　at　the　problem　of　dishonest　recommendation　behavior　in　indirect　trust　evaluation,　a　consistent　optimization　strategy　of　node　recommendation　behavior　is　designed.　Finally,　the　comprehensive　trust　evaluation　value　of　the　terminal　node　is　obtained　according　to　the　direct　trust　evaluation　and　the　indirect　trust　evaluation.　The　effectiveness　of　this　scheme　is　verified　by　simulation　experiments.　©　2022　ACM.