Based on the drinking water quality survey data of China's major cities, the existing disease burden calculation method was improved and disability-adjusted life years (DALYs) was taken as the end of evaluation to assess the health risk of arsenic contamination level. The results showed that the concentration of arsenic in drinking water of major cities in China was very low (0.53 μg·L), far below the national limit (10 μg·L) and the total lifetime cancer incidence was 1.76×10. The order of risks of different kinds of cancers was:skin cancer (1.53×10) > lung cancer (2.25×10) > liver cancer (2.30×10) > bladder cancer (1.34×10) and the average disease burden was 1.91×10 per person-year. Among them, skin cancer and lung cancer accounted for 70.2% and 29.0% respectively, and the disease burdens of bladder cancer and liver cancer were negligible, but the overall cancer risk was still higher than the recommended level of 10 per person-year by WHO. Although the arsenic level of drinking water in China was not high, the risk of cancer could not be ignored. Thus more effective and feasible measures should be taken to reduce arsenic concentration to protect people's drinking water safety in the future.