The invention discloses an oil screen pipe with a square screen net. The oil screen pipe comprises a screen pipe body. The upper end of the screen pipe body is provided with an oil inlet. The lower end of the oil inlet is fixedly connected with an upper end of a hand-operated valve. The lower end of the hand-operated valve is provided with a flow meter installed in an inner cavity of the screen pipe body. A display screen of the flow meter is installed in a groove of the screen pipe body. An inner cavity of the screen pipe body is fixed with a welding pipeline. An outlet of the pipeline faces a center of a first screen net. Outer walls on left and right sides of the screen pipe body are provided with screen net storage grooves. Two ends of a sliding groove of the screen net are in butt joint with the screen net storage grooves. The sliding groove of the screen net is arranged in the inner wall on the front and back side of the screen pipe body. The first screen net is hinged onto a second screen net. The oil screen pipe has the following beneficial effects: through readings of the flow meter, a judgment is made as to whether the oil screen pipe is blocked or not; the spare screen net can be replaced without stopping work of machinery; and sands can be timely cleared out.