Objective To analyze the cadmium level of main food and to assess the safety of dietary exposure of cadmium. Methods A total of 875 samples of 11 categories of food were collected from Xiacheng District. Cadmium contents in food were determined and then the cadmium intake and margins of safety (MOS) were calculated among Xiacheng residents and a risk assessment was conducted. Results Cadmium was detected in 695 of 875 samples(79.43%). 55 out of 796 samples with cadmium content above national standards(6.91%)The highest cadmium content among 11 categories of food was seaweed (4.510 0 mg/kg). The cadmium exposure of Xiacheng residents from main food categories were 15.785 8 μg/kg BW, which was below the provisional tolerable monthly intake (25 μg/kg BW), and the MOS was above 1, so the health risk of dietary exposure was low. The highest contributions were from aquaculture (43.97%), edible mushroom (17.42%), and rice (16.48%). Although consumption of aquaculture and edible mushroom was very low, the contribution was high due to the serious cadmium contamination. Aquaculture and edible mushroom were identified as high risk food for cadmium exposure. Conclusion The level of dietary cadmium exposure from the main food was safe in general. However, more attention should be paid to the high risk food of aquaculture and edible mushroom.