This study studied the dietary structure, lead (Pb) contents and exposure of the diets of the residents in the mining-affected areas of Nandan County in summer (July to August) and winter (November to December). The weighing method and the Chemical Analysis Method were applied to determine the daily intake amount of trace element Pb in the diets of the residents in the mining-affected areas and a contrast area, and subsequently estimated the Pb exposure of the diets of the residents. Based on the Provisionally Tolerable Weekly Intake (PTWI) and Margin of Exposure (MoE), the risk of Pb poisoning driven by the dietary intake of the residents in the study areas was determined. Among the food types, rice and rice products, vegetables, meat and meat products were the major contributing factors. In the mining-affected areas, Pb contents in meat and meat products ranked the top (2.47 μg/g) among the food types. The Pb contents in rice and rice products, vegetables, and meat and meat products in the mining-affected areas were significantly different from those in the contrast area. The average intake amounts of Pb in all kinds of food of the residents in the mining-affected areas (Chehe Town, Dachang Town and Zhanglao Town) were 958.6 µg/d, 1178 µg/d and 813.7 µg/d, respectively. According to the MoE method, current study confirmed high health risk due to Pb contamination in the diets of the residents in these mining-affected areas. From the dietary contribution rate perspective, meat was the main source of Pb intake of the residents in the mining-affected areas. To reduce the health risk induced by excessive Pb exposure in the dietary intake, local residents should consume more fish and grains instead of meat.