The aim of this study was to investigate the molecular structure of sPLA2 and its mechanism of action in hepatocellular carcinoma. The expression system of sPLA2 and its related proteins was constructed by gene cloning and protein expression techniques, and the molecular structure of sPLA2 was analyzed in detail. The effects of PLA2G12B protein level on proliferation, apoptosis and migration of hepatocellular carcinoma cells were studied by RNA interference and gene overexpression in vitro. The role of PLA2G12B protein level regulation on tumor growth and metastasis in vivo was further verified by establishing an animal model of hepatocellular carcinoma. It was found that the molecular structure of sPLA2 is highly conserved, and the amino acid sequence of its active center remains consistent across species. In hepatocellular cancer cell lines, overexpression of PLA2G12B protein significantly promoted cell proliferation and migration, while decreased expression level led to slower cell proliferation and increased apoptosis. The results indicate that PLA2G12B protein has become a new target for hepatocellular carcinoma therapy, and its down-regulation is expected to be an effective strategy to inhibit tumor growth and metastasis.