The invention provides an LED fluorescent powder spraying method and an LED fluorescent powder spraying device. The device comprises a powder spraying device, a base platform, a fluorescent powder box and a controller, wherein a rotary platform deck on the base platform rotates to enable an LED to be in uniform contact with fluorescent powder fluorescent powder sprayed out by the powder spraying device; after powder spraying, a heating device started by the rotary platform deck enables diluent in fluorescent powder mixed glue solution to volatilize rapidly; at the same time, the liquid inlet manner adopts an automatic fluid supplement system; through detecting the liquid level of the fluorescent powder mixed glue solution in a glue storage cylinder, the situation that whether the fluorescent powder mixed glue solution needs to be supplemented from the fluorescent powder box is automatically judged to ensure that certain volume range of solution is always stored in the glue storage cylinder, so that atomized mixed glue solution is ensured to be sprayed out to realize spraying uniformity. According to the LED fluorescent powder spraying method and the LED fluorescent powder spraying device, the method is reasonable, the conception is skillful, the uniform powder spraying effect is remarkable, and the market prospect is wide.