Abstract: To analyze the heat-transfer performance of dispersed phase in continuous phase within ORC direct contact evaporator for low-temperature waste-heat power generation, the environmental-friendly refrigerant R245fa and heat-transfer oil THERMINOL_66 were respectively taken as the dispersed phase and continuous phase, with which the influence of following factors on the volumetric heat-transfer coefficient of ORC direct contact evaporator was analyzed, such as the initial temperature difference, the refrigerant flow rate and the oil flow rate, etc. Results show that the volumetric heat-transfer coefficient rises first, drops later on, and finally tends to be stable, always being larger than the coefficient at initial period; for a fixed refrigerant flow rate and initial temperature difference, the flow rate of heat-transfer oil should be controlled within a narrow range so as to obtain higher volumetric heat-transfer coefficient of ORC direct contact evaporators.