The invention relates to a crude oil tank and a use method. The crude oil tank comprises a tank body for storing crude oil and an oil pump mounted outside the tank body, wherein the tank body is connected with an oil discharging pipe; one end, far away from the tank body, of the oil discharging pipe is connected with the oil pump; multiple recoil oil pipes are arranged in the tank body; the central axial lines of the recoil oil pipe are arranged in a radial direction of a circle taking the center of the tank body as a circle center; a plurality of spraying heads for spraying oil in a tangential direction of the circle taking the center of the tank body as a circle center are arranged on the recoil oil pipes along axial directions of the recoil oil pipes; orientations of the spraying headson adjacent recoil oil pipes are the same; the oil pump is communicated with an oil separation piece communicated with the multiple recoil oil pipes; control valves for controlling the spraying headson the recoil oil pipes to be separated from the oil separation piece are arranged on the recoil oil pipes; the oil separation piece is communicated with an output pipe for conveying oil pumped by theoil pump to other places; a valve for controlling opening and closing of the output pipe is arranged on the output pipe. The crude oil tank can uniformly mix the crude oil in the tank body with precipitates, and the equipment investment cost is low.