The　slide　valve　is　used　to　regulate　the　capacity　of　a　single　screw　refrigeration　compressor.　However,　many　cases　have　shown　that　it　always　stops　doing　the　regulation　a　short　period　of　time　after　the　boot-start　of　the　compressor.　This　failure　might　be　attributed　to　the　thermal　and　gas　force　deformation　of　the　slide　valve　or　the　cylinder.　In　this　paper,　simulation　of　thermal　and　gas　force　deformation　of　a　single　screw　refrigeration　compressor　with　finite　element　method　was　carried　out.　Results　showed　that　size　of　the　deformation　was　far　bigger　than　the　clearance.　It　means　a　hard　contact　between　the　slide　valve　and　its　groove.　It　was　believed　that　the　deformation　resulted　in　the　failure　of　the　slide　valve.　©　The　author(s)　and/or　their　employer(s),　2013.