The invention relates to a cavity-type light emitting diode lamp. A cooler is an enclosed metal cavity which is internally filled with a liquid working medium with latent heat of vaporization; a microgroove group metal plate is arranged on the cavity wall of the side or bottom of the metal cavity, and the periphery of the metal cavity is fixedly connected to the cavity wall of the metal cavity in a sealing mode; the back side of the metal cavity is provided with a microgroove group which is sealed in the cavity inward, and the frontage of the metal cavity is outward; the microgroove group is provided with a plurality of open-type microgroove channels, thus an open-type microgroove group is formed; an LED (light emitting diode) chip is encapsuled on the frontage of the metal plate, the light emitting surface of the chip is outward, the outer surface of the cavity wall at the top of the metal cavity is fixedly connected with a power supply, and the chip is electrically connected with a power supply; and the outer side wall of the cooler, except for the microgroove metal plate, is provided with fins. When the lamp works, the heat transfer process is intensified by high-strength minuteness scale composite phase-change of nucleate boiling of the liquid working medium, the liquid working medium is changes into steam, and the heat is taken away, expands on the surface of the metal cavity, and is released into the environment through the fins. The problems of insufficient heat radiation, over-heavy weight and overlarge volume of the existing LED lamp chip are solved.