The invention discloses a quantum dot composite fluorescent particle including quantum dots, a mesoporous material, and a water-blocking and oxygen-blocking material. The quantum dots are distributed in the mesoporous material, and the water-blocking and oxygen-blocking material is filled in the gaps between the quantum dots and the mesoporous material. The quantum dot composite fluorescent particles may also include metal nanoparticles distributed within the mesoporous material and/or a blocking layer coating the outer surface of the mesoporous material. These features greatly improve the water and oxygen blocking properties and thus, the stability of the quantum dot composite fluorescent particles. The metal nanoparticles help the quantum dots capture more blue lights due to the localized surface resonance plasma and consequently improve the utilization ratio of the blue lights. The quantum dot composite fluorescent particle can then be integrated into an LED module to improve its service life.