A　numerical　simulation　has　been　conducted　to　investigate　the　heat　and　mass　transfer　in　the　adsorption　process　of　an　annular　cavity　bed.　The　silica　gel　and　the　water　was　taken　as　the　working　pair.　The　2D　model　of　the　heat　and　mass　transfer　has　been　established　for　the　adsorption　problem.　To　clarify　the　cooling　effect　of　different　situations,　the　air　cooling　mode　and　the　water　cooling　mode　were　considered　to　apply　onto　the　bed.　Based　on　the　numerical　results　the　change　of　the　temperature　and　the　vapor　concentration　of　the　bed　was　analyzed　and　discussed.　The　influence　of　the　bed　layer　porosity　and　the　evaporation　temperature　on　the　performance　was　examined　too.　The　results　have　revealed　that　the　bed　temperature　increased　largely　at　the　first　400　seconds　of　the　adsorption　time.　This　time　corresponded　to　the　rapid　adsorption　and　the　large　amount　of　the　heat　generation.　Beyond　a　summit,　the　temperature　of　the　bed　decreased　gradually　while　the　bed　concentration　kept　increasing.　The　bed　layer　porosity　affected　the　adsorption　only　in　a　small　scale,　while　increasing　the　evaporation　temperature　promoted　the　adsorption　largely.