The invention relates to a float valve and belongs to the technical field of chemical equipment for gas-liquid mass transfer separation in the chemical industry. The float valve comprises a quadrangular valve cover and two valve legs and is characterized in that an embossment high in the middle and low in the periphery is formed in the bottom of the valve cover; at least one tongue hole is formed in the valve cover, and an obliquely arranged baffle is arranged at the tongue hole of the top of the valve cove; teeth are arranged on two opposite sides of the valve cover; the valve legs are arranged at the bottom of the valve cover, close to the other two sides; the valve legs are inclined outwards respectively and are made of elastic metal materials; a valve foot is arranged at the lower end of each valve leg; a corrosion resistant coating coats the outer surface of the float valve. According to the float valve, the vibration during use can be effectively reduced and the service life of the float valve can be prolonged.