With　the　rapid　development　of　the　Internet　and　technological　innovation,　the　number　and　resources　of　computers　accessed　in　P2P　(Peer　to　Peer)　peer-to-peer　networks　are　increasing.　Another　important　feature　of　P2P　is　to　change　the　current　Ethernet　centric　state　of　the　Internet,　return　to　＇decentralization＇,　and　return　power　to　users.　Its　openness,　anonymity　and　autonomy　increase　the　possibility　of　security　attacks　by　malicious　nodes.　For　example,　malicious　nodes　providing　false　services　will　affect　normal　transactions　between　P2P　network　nodes.　This　has　affected　the　development　of　P2P　applications　to　a　certain　extent.　In　view　of　the　existing　P2P　network　node　security　problems,　can　not　deal　with　the　node　collusion　attacks,　joint　fraud　and　other　issues,　this　paper　proposes　a　new　trust　calculation　method.　This　method　draws　on　the　basic　elements　of　social　psychology　about　establishing　intimate　relationship　between　people,　considers　the　influence　of　node　behavior　on　trust,　and　uses　aggregated　trust,　current　trust,　feedback　trust　and　cumulative　abuse　trust　to　calculate　and　update　the　trust　value,　so　as　to　improve　the　dynamic　adaptability　and　fault　tolerance　of　peer-to-peer　networks.　©　2023　SPIE.