The invention discloses a manufacturing method of an LED lamp bead, which comprises the steps of: firstly, sieving first fluorescent powder and second fluorescent powder, which are large in particle size range, into 3 to 10 fluorescent powder piles different in particle size by adopting a gas flow sieving device; and after uniformly mixing the first fluorescent powder and the second fluorescent powder, which are in the same particle size range, mixing the mixture with packaging glue, after defoaming and uniformly stirring, preparing a fluorescent adhesive, dropwise adding the fluorescent adhesive into a bracket on which an LED chip is arranged, and baking and curing to obtain the LED lamp bead. After the fluorescent powder is sieved by adopting the gas flow sieving device, consistency of the particle sizes of fluorescent powder particles is obviously promoted, so that the mixed fluorescent powder is small in particle size range and is easier to uniformly mix with the packaging glue, requirements for equipment and the operation difficulty in the fluorescent adhesive stirring process are reduced, light intensity and light color consistency of the LED lamp bead are high, the concentration degree of the same batch of products is high, and a good rate of a packaged product is improved; and the fluorescent powder sieving device and a sieving mode are high in automation degree, simple in operation and suitable for large-batch industrial production.