According　to　the　analysis　of　heat　balance,　about　1/3　of　the　fuel　combustion　heat　is　taken　away　into　the　ambience　by　exhaust　gas　of　diesel　engine.　In　this　article,　to　improve　the　using　level　of　the　fuel＇s　combustion　heat,　a　two　stage　single　screw　expander　organic　Rankine　cycle　(ORC)　system　has　been　used　to　recover　the　waste　heat　from　exhaust　gas　of　a　certain　turbine　diesel　engine.　In　this　article,　physical　model　of　the　recovery　system　was　built　at　first,　then　the　T-S　curve　was　drawn,　at　last,　REFPROP　was　used　to　calculate　thermodynamics　parameter　in　different　state　point　of　this　system,　and　analyze　the　whole　system＇s　thermodynamics　character.　By　analyzing,　the　evaporation　temperature　of　this　system　should　be　optimized　to　get　the　relatively　evaporation　press;　by　calculating,　it　could　be　seen　that　the　middle　heater　in　this　system　should　be　taken　away　to　improve　the　economy　of　this　scheme.　This　scheme　should　supply　a　direction　for　the　exhaust　heat　recovery　of　diesel　engine.