Provided is a combined pharmaceutical composition of HF and an Artemisia annua sesquiterpene lactone compound for treating cancers. The active ingredients of the combined pharmaceutical composition consist of HF and an Artemisia annua sesquiterpene lactone compound. HF and ATS have significant synergistic effect. The activity of the combined pharmaceutical of HF and ATS is comparable or even higher than that of the anti-cancer drug 5-FU.