The　complex　and　changeable　working　conditions　of　compressed　natural　gas　(CNG)　engines　have　brought　great　challenges　to　the　efficient　recovery　of　waste　heat　energy.　The　dual　loop　organic　Rankine　cycle　(DORC)　system　can　effectively　recover　and　utilize　CNG　engine　waste　heat　due　to　its　structural　advantages.　Determining　the　nonlinear　variations　between　operating　parameters　and　thermodynamic　performance　serves　as　the　basis　for　obtaining　the　thermodynamic　performance　limits　of　the　DORC　system.　However,　traditional　analysis　methods　have　obvious　limitations　in　this　area.　Based　on　the　bilinear　interpolation　algorithm,　this　paper　comprehensively　analyzes　and　evaluates　the　nonlinear　and　strong　coupling　characteristics　between　operating　parameters　and　net　power　output,　thermal　efficiency,　and　exergy　destruction.　In　addition,　the　comprehensive　thermodynamic　performance　limits　of　the　DORC　system　have　a　critical　effect　on　its　engineering　application　yet　have　not　been　thoroughly　and　comprehensively　optimized.　Therefore,　this　paper　proposes　an　equilibrium-based　thermodynamic　high-dimensional　evolutionary　many-objective　optimization　(EMO)　method　for　the　DORC　system.　The　optimal　thermal　efficiency,　net　power　output,　and　total　exergy　destruction　of　the　DORC　system　reached　37.11　kW,　14.27%,　and　104.58　kW,　respectively.　Based　on　the　optimization　results　under　equilibrium　and　unequilibrium　weight,　the　dominant　relationship　between　the　different　thermodynamic　performances　of　the　DORC　system　is　then　analyzed.　This　research　can　provide　a　direct　reference　for　analyzing　and　optimizing　the　comprehensive　thermodynamic　performance　of　the　DORC　system.　(c)　2021　Elsevier　Ltd.　All　rights　reserved.