The invention discloses a modified inverse-opal photonic crystal microsphere used for enriching, purifying and detecting AFB1, and a preparation method and an application of same. The modified inverse-opal photonic crystal microsphere can effectively and specifically enrich and purify aflatoxin. With 30 [mu]l of the modified inverse-opal photonic crystal microsphere as an immunoaffinity material, enrichment quantity of the AFB1 can reach up to 50 ng, and elution rate of a standard substance can reach 90%. The preparation method is simple, is low in raw material cost and can save cost. The modified inverse-opal photonic crystal microsphere has good effect of enriching, purifying and detecting the AFB1 in agricultural products. A process of packing columns is avoided, so that the use method of the microsphere is more simple and convenient.