The invention discloses a mixed photonic crystal composite material based on folic acid modification and application. The mixed photonic crystal composite material is prepared from a mixed photonic crystal carrier and folic acid loaded on the carrier, wherein the mixed photonic crystal is prepared from polyethyleneglycol diacrylate inverse opal skeleton and methacrylate gelatin and magnetic nanoparticles with which skeleton pores are filled. The mixed photonic crystal composite material is applied to the detection for myeloid leukemia drug-resistance cells. The remarkable advantage of the mixed photonic crystal composite material is that the composite material is of a nano ordered structure, the specific surface area is large, the mechanical strength is high, and the stability is strong, and the composite material has the excellent biological compatibility and the magnetic responsiveness, and is easy to control. The composite material is applied to the detection for the drug-resistancecells, the myeloid leukemia drug-resistance cells can be specifically, sensitively, simply and effectively captured, and drug-resistance cell strains with good biological activity are guaranteed, andthe myeloid leukemia drug-resistance cells can be effectively enriched and separated after being captured only if a magnetic field is applied.