Abstract: This study aims to establish a new molecular identification technology, it is applied to the identification of Pheretima aspergillum products in the Chinese herbal market. A total of 5 varieties of Pheretima aspergillum and its confusing varieties were collected, sample DNA was extracted, and 20 random primers were used for PCR-RAPD reaction to select suitable amplification primers. Finally, primers with clear amplification bands, good reproducibility, good polymorphism, and stable reaction procedures were used to identify Pheretima aspergillum and its confusing products. The results showed that three primers were finally selected as primers to identification.Primers DL05（5’-CATCCCCCTG-3 ’） were amplified, and the bands of about 750 bp and 1000 bp were amplified;primers DL12（5’-TGAGCCTCAC-3’） were amplified, and the bands of about 300 bp and 500 bp were amplified;primers DL18（5’-TTCCGAACCC-3’） were amplified, and the bands of about 1 000 bp and 1 800 bp were amplified. The primer DL12 was selected as the amplification primer, and the reaction system was optimized by a single factor for the Mg²⁺ concentration, dNTPs concentration, primer concentration and Taq DNA polymerase concentration in the system. Optimize the RAPD reaction system to obtain the best reaction conditions: Mg²⁺ concentration is 1.0 mmol/L, dNTPs concentration is 0.2 mmol/L, primer concentration is 0.3 μmol/L,Taq DNA polymerase concentration is 1.5 U. The RAPD technology used in this study is simple and reliable, and can be applied to the identification of Pheretima aspergillum and their confusing products on the herbal market, which provided a scientific basis for the research on the identification of Pheretima aspergillum.