Objective: To investigate the effects of different macrophage polarization phenotypes on the proliferation and metastasis of hepatocellular carcinoma (HCC) cells and their underlying mechanisms. Methods: THP-1 suspension cells were induced to adhere and differentiate into M0 macrophages by treatment with phorbol 12-myristate 13-acetate (PMA). Subsequently, polarization into M1 and M2 macrophages was achieved by stimulation with lipopolysaccharide (LPS) and interferon-γ (IFN-γ), or interleukin-4 (IL-4) and interleukin-13 (IL-13), respectively. Quantitative real-time polymerase chain reaction (qPCR) was performed to analyze the mRNA expression levels of specific marker genes related to M1 and M2 macrophage phenotypes. The Cell Counting Kit-8 (CCK-8) assay was used to evaluate the effect of macrophage culture supernatants on the growth of hepatocellular carcinoma (HCC) cells. The effect of macrophage culture supernatant on the metastatic ability of liver cancer cells was analyzed by Transwell assay. Western blot analysis was carried out to determine the expression and activation levels of key proteins involved in relevant signaling pathways. Results: qPCR analysis demonstrated that the mRNA expression levels of M1-associated markers, including HLA-DR, TNF-α, and CXCL-9, were upregulated in vitro-induced M1 macrophages (P < 0.05). In contrast, the expression levels of MRC1 and HGF, markers associated with M2 macrophages, were increased in vitro-induced M2 macrophages (P < 0.05), with distinct morphological features validating successful polarization. CCK-8 assay results indicated that, in both SMMC7721 and Sk-hep1 cell lines, co-culture with M2 macrophage supernatants enhanced cell proliferation compared with M1 groups and the blank control group (P < 0.05). Co-culture with M1 macrophage supernatants reduced SMMC7721 proliferation (P < 0.05) but showed no significant effect on Sk-hep1 compared to the control. Transwell migration assays further confirmed that M2 macrophage supernatants markedly promoted the migration capacity of both SMMC7721 and Sk-hep1 cell lines compared to M1 (P < 0.05), with M1 showing no pro-migratory effect. Western blot analysis indicated that M2 macrophages likely promote the growth and metastasis of HCC cells by activating the ERK and AKT signaling pathways, whereas M1 macrophages suppress these pathways. Conclusion: M2 macrophages may promote the proliferation and metastasis of HCC cells, potentially through activation of the ERK and AKT signaling pathways, while M1 macrophages may inhibit these processes by suppressing ERK/AKT signaling.