In　order　to　take　full　advantage　of　the　waste　heat　from　a　diesel　engine,　a　set　of　dual　loop　organic　Rankine　cycle　(ORC)　system　was　designed　to　recover　exhaust　energy　and　waste　heat　of　the　coolant　for　a　six-cylinder　vehicle　diesel　engine.　The　dual　loop　ORC　system　consists　of　a　high　temperature　(HT)　loop　ORC　system　and　a　low　temperature　(LT)　loop　ORC　system,　and　R245fa　was　selected　as　working　fluid　for　the　dual　loop　ORC　system.　The　HT　loop　ORC　system　was　used　to　recover　the　exhaust　energy,　while　the　LT　loop　ORC　system　was　for　recovering　the　waste　heat　from　the　coolant　and　the　released　heat　in　condensation　process　of　the　HT　loop　ORC　system.　Through　the　engine　test,　the　performance　of　the　dual　loop　ORC　system　for　waste　heat　recovery　was　discussed　on　the　basis　of　the　analysis　on　waste　heat　characteristics　under　engine　various　operating　conditions.　The　results　show　that,　under　engine　entire　operating　conditions,　the　maximum　net　power　output　of　the　dual　loop　ORC　system　is　26.58　kW,　the　maximum　thermal　efficiency　can　reach　up　to　14.62%;　and　the　combined　system　of　diesel　engine　and　dual　loop　organic　Rankine　cycle　has　better　fuel　economy　and　power　performance.　©,　2015,　Beijing　Institute　of　Technology.　All　right　reserved.