The invention discloses a device for measuring the water content of crude oil through electric dehydration centrifugation. The device comprises a device shell, a central shaft rod and a transverse support rod, wherein the central shaft rod is arranged inside the device shell; the transverse support rod is arranged on the top of the central shaft rod; the central shaft rod is connected inside the device shell through a bearing; the device shell is internally provided with a rotating motor; a belt pulley is arranged on the spindle of the rotating motor; the belt pulley is connected with the middle part of the central shaft rod through a transmission belt; two ends of the transverse support rod are respectively provided with one testing device; anode conductive rods are arranged in the centers of the testing devices; cathode conductive rings are arranged on the outer walls of the testing devices. The invention further discloses a testing method for measuring water content of crude oil through electric dehydration centrifugation. The device disclosed by the invention is excellent and precise in measuring performance, simple in structure, environmentally friendly and energy-saving, convenient to popularize, precise and reliable in water content measuring result of the crude oil, good in use stability, good in applicability and good in practicability, the varieties of crude oil of which the water content can be tested are widened, and the testing process is relatively simple, low in cost and energy-saving and environmentally friendly.