Magnetic polystyrene nanospheres have uniform particle size, smooth surface, excellent hydrophobicity and non-biodegradability. Is not dissolved or swollen by general solvents, conducive to application and recovery; For some substances such as proteins, dyes, affinity Chemicalbook sites have excellent binding ability; Large specific surface area, strong adsorption, good cohesion, suitable for some substances as fixed carrier; The particle size has good controllability, high surface reaction activity and high adsorption efficiency for chromatography.