The invention discloses a method for detecting the purity and the consistency of conventional rice varieties. The method comprises the following steps of planting every same variety of rice in an array mode, wherein any stain of rice is marked as RaCb; extracting leaf tissue of every strain of rice in the same row and extracting leaf tissue of every strain of rice in the same column when the rice grows to the booting stage and extracting DNA (Deoxyribose Nucleic Acid) according to a conventional CTAB (Cetyl Trimethyl Ammonium Bromide) method after mixture; performing SSR (Simple Sequence Repeat)-PCR (Polymerase Chain Reaction) amplification to obtain amplified products and performing electrophoretic separation and dyeing; performing amplification on two or more than two pairs of SSR primers according to the belt type of the amplified products to obtain an intersection of the a row and the b column of a special belt to be determined as a suspected special plant; determining a real special plant according to the size of the special belt of a mixed sample on the same primer or a single strain of SSR fingerprint spectrum corresponding to the intersection. Compared with phenotypic character based rice variety consistency tests, the method for detecting the purity and the consistency of the conventional rice varieties is simple and convenient and rapid, the workload is reduced, the efficiency is improved, and the cost is reduced.