Based　on　the　analysis　of　computation　methods　and　heat　transfer　processes　of　the　parabolic　trough　receiver　running　in　steady　state,　a　two-dimensional　empirical　model　was　developed　to　investigate　the　thermal　performance　of　heat　loss　of　parabolic　trough　receivers　under　steady　state　equilibrium.　A　numerical　simulation　was　conducted　for　the　parabolic　trough　receiver　involved　in　a　literature.　Comparisons　between　numerical　and　experimental　results　show　that　the　empirical　model　is　accurate　enough　and　can　be　used　to　investigate　the　thermal　performance　of　heat　loss　of　parabolic　trough　receivers.　The　thermal　performance　of　heat　loss　of　UVAC3　and　the　new-generation　UVAC2008　was　investigated　respectively.　The　simulation　results　show　that　selective　coatings　and　annular　pressure　influence　the　thermal　performance　of　heat　loss　of　parabolic　trough　receivers　greatly,　wind　velocity　influences　the　thermal　performance　of　thermal　loss　of　parabolic　trough　receivers　only　a　little　in　contrast　with　the　emittance　of　selective　coatings　and　air　pressure　in　annular　space.　And　the　thermal　performance　of　thermal　loss　of　the　new-generation　parabolic　trough　receiver　has　been　improved　in　a　large　amount.