Thirteen Chinese cabbage (Brassica rapa) hybrid cultivars and 26 parental inbred lines were used as experimental materials to screen for primers producing hybrid and parental complementary bands and for primers with high polymorphism information contents and low genotype frequencies. A total of 18 pairs of core primers were designed to identify the purity of Chinese cabbage. There was no significant difference in the purity percentage measured between different loci of the same strain. The fingerprint obtained by the amplification of each locus could be used to identify purity to obtain an authentic purity percentage. Curve mapping and significance analyses were conducted using the purity percentage of eight different seed samples and confirmed a sampling seed number of 96. The results of the purity test were verified by comparison with the grow-out test (GOT) using molecular markers. In conclusion, the simple sequence repeat (SSR) detection system could be used for the rapid identification of the purity of the tested Chinese cabbage hybrids.