Dyed polystyrene microspheres are based on white polystyrene microspheres and are prepared by a unique internal dyeing process. The internal dyeing process can minimize dye leakage and guarantee storage stability, and hence improve covalent bonding coupling efficiency and detection sensitivity. Dyed polystyrene microspheres have surface carboxyl groups that can be coupled with antigens, antibodies, etc., and are often used in lateral immunochromatography and latex agglutination tests. We have microspheres covering rainbow series colors, which can meet various experimental needs in the field of industrialization and scientific research.