The invention aims at providing a simple and efficient method for preparing a high-performance magnetic fluorescent composite
microsphere. Due to the existence of Fe3O4
magnetic nanoparticles, electrons of a fluorescent substance which are located at a conductance band are subjected to
electron transfer in a process of returning to a
valence band, the electrons of the conductance band are transferred on the Fe3O4
magnetic nanoparticles and
fluorescence is subjected to
quenching. The method provided by the invention is emphasized on solving the problem that the Fe3O4
magnetic nanoparticles cause large influence on the
fluorescence performance of the fluorescent substance in a process of preparing a magnetic fluorescent
microsphere. According to the preparing method provided by the invention, through changing a
doping sequence and adopting different
doping methods, the prepared magnetic fluorescent
microsphere can minimize the influence on the fluorescent substance caused by
magnetism on the basis of ensuring the magnetic fluorescent microsphere to have excellent magnetic property in
actual use and enable the
fluorescence performance to be optimal; and the fluorescent substance is introduced by adopting a high-temperature swelling method, so that fluorescent substances inside the microsphere cannot leak, and the stability of fluorescent signals is ensured. The mean particle
diameter of the prepared magnetic fluorescent composite microsphere is 5-50 microns, and the particle
diameter is even and has perfect appearance.