Abstract: The mechanical performance of the  70 mm centrifugal extractor used in nuclear industry is investigated and its hydraulic characteristics in a H 2O kerosene system are tested. When the centrifugal extractor runs, its temperature rise is not high, the vibration is little, the noise is low. It can be disassembled immediately after shutdown. When the A/O ratio ranges from 1/18 to 16/1, the maximum of total throughput can reach 290 L/h.