Objective To summarize the effect of lenvatinib + transarterial chemoembolization (TACE) + programmed cell death protein-1 (PD-1) antibody in the treatment of hepatocellular carcinoma with main portal vein tumor thrombus and cavernous transformation. Methods In this study, we reported the clinical data of four patients with hepatocellular carcinoma with main portal vein tumor thrombus and cavernous transformation who received conversion therapy with lenvatinib combined with TACE and PD-1 antibody in West China Hospital. Results Among the four patients, two patients achieved complete response and two achieved partial response; tumor markers were significantly decreased after combination treatment. However, all four patients failed to undergo hepatectomy. ConclusionsLenvatinib + TACE + PD-1 antibody is effective for hepatocellular carcinoma with main portal vein tumor thrombus and cavernous transformation. However, there are still many problems worthy of further discussion.