With　the　continuing　development　of　smart　grids　and　energy　storage　technologies,　renewable　energy　accommodation　has　been　effectively　improved.　However,　due　to　high　investment　costs,　public　microgrid　programs　do　not　have　enough　incentive　for　users　to　invest,　so　that　flexible　energy　storage　devices　cannot　be　fully　utilized.　This　paper　first　designed　a　behind-the-meter　microgrid　system　consisting　of　a　variety　of　flexible　devices,　introduced　an　architecture　of　the　behind-the-meter　microgrid　system,　and　further　introduced　a　blockchain-based　system　operation　to　build　a　data-sharing,　system-governing　behind-the-meter　microgrid　system.　Subsequently,　this　paper　proposed　an　energy　block　concept　and　its　trading　mechanism　applicable　to　the　behind-the-meter　microgrid　system,　built　an　optimization　model　with　the　objective　function　of　social　welfare　maximization,　and　designed　the　flow　of　the　energy　block　one-day　trading　algorithm　so　as　to　meet　the　needs　of　users　for　segmented　transactions　in　behind-the-meter　microgrid　systems　and　solve　the　mismatch　between　the　existing　P2P　energy　trading　and　the　behind-the-meter　microgrid　system.　Finally,　the　simulation　examples　were　presented　to　discuss　the　overall　operation　of　the　behind-the-meter　microgrid　system　and　the　trading　characteristics　of　different　users　described　in　this　paper　to　demonstrate　the　effectiveness　of　the　described　algorithm　and　to　show　the　important　role　that　the　behind-the-meter　microgrid　system　and　its　energy　block　trading　model　play　in　the　efficient　use　of　distributed　power　and　the　increase　of　social　welfare.　©　2021　Chin.　Soc.　for　Elec.　Eng.