A centrifuge with an electric motor (46), composed of a centrifuge outer frame (47), a heavy liquid collecting tank (18), a lower hollow shaft (22), centrifugal units, an upper hollow shaft (38), and a light liquid collecting tank (41). The heavy liquid collecting tank, the lower hollow shaft, the upper hollow shaft, and the light liquid collecting tank are all fixed to the centrifuge outer frame, the centrifugal units are fixed between the upper hollow shaft and the lower hollow shaft, the motor is connected to the upper hollow shaft and drives the upper hollow shaft to rotate, the upper hollow shaft is fixed to two or more centrifugal units connected in series and drives the centrifugal units to rotate, a hollow portion of the upper hollow shaft communicates with the light liquid collecting tank, centrifugal units are fixed to the lower hollow shaft and drive the lower hollow shaft to rotate, the heavy liquid collecting tank is a casing formed between the centrifuge outer frame and the centrifugal units. The centrifugal of the present invention is simple in structure, small in volume, low in power consumption, thorough in separation, convenient in operation, and high in practicability.