This　paper　introduces　the　principle　of　the　engine　waste　heat　recovery　system.　The　organic　Rankine　cycle　(orc)　system　is　proposed　to　improve　the　efficiency　of　waste　heat　recovery.　GT-power　software　is　used　to　make　a　DI　engine　model　of　493ZLQ3.　The　model　simulates　the　exhaust　temperature　on　the　brake　power　curve　and　brake　torque　curve　based　on　the　optimized　results,　and　put　a　comparison　with　the　test.　The　results　show　that　the　error　range　of　the　simulation　results　is　5%　compared　with　the　test　results.　Therefore,　the　results　of　the　simulation　and　analysis　can　afford　valuable　reference　for　calculating　the　entire　power　system.　The　whole　power　system　can　obtain　the　output　net　work　of　2.67　kW.　©　2011　IEEE.