The utility model discloses a heat dissipation mechanism of LED ceiling light, including aluminium base board, the reflector is installed to aluminium base board lower extreme, and the upper end is equipped with LED driving box, and there is the heat -conducting cylinder aluminium base board upper end along the outer wall cover, and the heat -conducting cylinder upper end is radial a plurality of the connected in stars that are equipped with, installs the graphite heat -conducting plate in the strip connected in star, and the radiating bottom plate is installed to the heat -conducting cylinder top, and radiating bottom plate upper end evenly distributed has convex wind -guiding mouth with a plurality of radiating fin of idol, last the opening to one side of radiating fin. The utility model has the advantages of simple and reasonable structure, installation convenient to use adopts to set up the heat -conducting cylinder design that has the graphite heat -conducting plate on aluminium base board, has improved heat -conduction speed effectively for heat that LED light -emitting component sent can be quick conduct to the radiator, and cold and hot air forms the convection current easily, has improved radiating rate and efficiency effectively, has guaranteed the life of LED ceiling light.