Abstract: A single-loop low-evaporative-pressure organic Rankine cycle（SLL-ORC）with jacket water and exhaust gas waste heat,absorbed by the two-phase zone and superheat zone of R245fa workpiece respectively,was proposed by using the matching relationship between the specific heat capacity of the workpiece and the waste heat source,and by compared with a pre-recuperative CO₂ trans-critical power cycle（PR-CTPC）of comparable complexity. The results show that the SLL-ORC performs better in recovering waste heat from engines with lower waste heat temperature and higher waste heat from jacket water. The waste heat recovery system has higher thermal efficiency with a theoretical maximum output work of 16.13 k W corresponding to an evaporative pressure of 910 k Pa and a superheat of 80 ℃. Based on this SLL-ORC configuration,an experimental rig was built to verify the feasibility of jacket water recovery in the two-phase region of R245fa work material. In the experimental test,the power generated by the system generator reaches 9.41 k W when both the waste heat source and the turbine speed do not reach the design value,effectively improving the absolute value of diesel engine thermal efficiency up to 2.98%.There is still much room for subsequent improvement if the system works in the design point.