To observe the curative effect of an acupoint application with a Dingqi analgesic patch on moderate to severe pain caused by liver cancer. Forty patients with moderate to severe pain caused by liver cancer were randomly divided into a treatment group (TG) and a control group (CG). Patients with moderate pain were given 100 mg qd of a sustainably released tablet of tramadol hydrochloride; patients with severe pain were given 4.2 mg q3d of the fentanyl transdermal system. The ashi points Ganshu (BL 18), Danshu (BL 19) and Qimen (LR 14) were chosen for the acupoint application intervention. CG patients were given a sham patch and TG patients were given a Dingqi analgesic patch. A visual analogue scale (VAS) was used before treatment and after 1, 3, 6, 9 and 12 days of treatment. The Karnofsky score was measured before treatment and after 12 days of treatment. Any main adverse reactions (e.g. nausea, constipation, dizziness and headache) were recorded after 6 and 12 days of treatment. Any skin side effects (i.e. skin irritation and allergic reactions) were recorded. The VAS in TG was significantly lower than that in CG after 3, 6, 9 and 12 days of treatment (P < 0.05). There was no significant difference in the Karnofsky score before treatment and after 12 days of treatment between CG and TG. There were also no significant differences in the main adverse reactions or skin side effects after 6 and 12 days of treatment between CG and TG (P > 0.05). The Dingqi analgesic patch can enhance the analgesic effect of tramadol and fentanyl.