The invention discloses a detection reagent and a typing method for the simultaneous genotyping of antigens of ABO blood group and specific A2, comprising four primers, two of which are sequential specific primers and the other two of which are inner comparison primers. The method can carry out simultaneous amplification to the blood group genes of the antigens of the ABO blood group and the specific A2 subtypes, which are very common among the Chinese population. The method can detect four alleles, A101, A102, B101 and O01, and six A2 alleles, A201, A202, A202, A204, A205 and A206, which arevery common among the Chinese population. Compared with the traditional detection methods, the detection method of the invention is fast, simple, practical, specific and sensitive, is suitable for the genetic identification of ABO blood groups of Chinese Han population and can be used in the research of the ABO blood group of human beings.