The invention discloses an optical fiber continuous liquid level sensor on the basis of end face reflection coupling. The sensor is an all-optical fiber sensor, which can be used for continuous measurement of the liquid level in a severe environment; a sensor probe part comprises a sending optical fiber bundle and a receiving optical fiber bundle, the two optical fiber bundles are wrapped in a shell, optical fibers are adhered through an adhesive, detection end faces of the optical fiber bundles are in a wedge shape, through the design of the wedge-shaped end faces, side coupling of the sending optical fiber bundle and the receiving optical fiber bundle can be achieved, the sensitivity of the sensor is improved, and droplet adhesion is lowered; by controlling the diagonal angles of the wedge-shaped end faces and the incident beam angles of the optical fibers, total internal reflection is conducted on emergent beams in the end faces of the optical fibers in the air, Fresnel reflection is conducted on emergent beams in the end faces of the optical fibers in a liquid, and when the liquid level is different, the total power of reflected beams is different, so that liquid level measurement is achieved. The sensor has the advantages of integrated structure and design without movable parts, high sensitivity, high safety and high reliability.