The　wrapping　of　plasmonic　metal　particles　with　silica　shell　is　considered　to　be　one　of　the　effective　means　to　make　full　use　of　hot　electrons　for　solar-hydrogen　conversion.　Ag@SiO2-TiO2　structures　with　different　shell　thicknesses　(2,　3,　5,　7　and　11　nm)　as　hot-electron　devices　were　fabricated,　and　their　local　electric　field　was　simulated　by　the　COMSOL　software.　A　novel　method　was　proposed　to　visually　characterize　the　migration　of　hot　electrons,　which　was　represented　by　multiphysics　coupling.　The　simulated　current　flow　indicates　the　transfer　direction　of　hot　electrons,　and　the　variation　of　electron-hole　concentration　implies　the　gain　and　loss　of　electrons.　The　results　demonstrate　that　the　applied　thinner　silica　shell　not　only　decreases　the　barrier　to　the　hot　electron　transport　out　of　shell,　but　also　intensify　local　electric　field.　When　the　silica　shell　thickness　is　2　nm,　the　amount　of　hot　electrons　migrated　out　of　shell　is　high,　such　that　the　photogenerated　electrons　in　TiO2　have　more　chances　for　jumping　to　higher　energy　states,　which　results　in　the　enhanced　separation　of　electrons　and　holes.　The　photocurrent　and　photovoltage　of　Ag@SiO2　(2　nm)-TiO2　were　respectively　1.68　and　1.54　times　higher　than　those　of　Ag-TiO2　denoting　the　highest　carriers＇　migration　and　utilization　efficiency.