Objective To assess the dietary exposure risk of mycotoxins for Beijing consumers, based on the mycotoxins contamination data during the cold storage period of Castanea mollissima which harvested in Huairou District, Beijing. Methods Castanea mollissima samples were collected from the 4 highest yielding townships in Huairou District. Samples were stored in a cold storage for 1 year and sampled once a month to determine the content of 21 kinds of fungal toxins. Based on the 2002 Beijing residents’ dietary consumption survey data, point estimation method, probability method and cumulative risk assessment modeling method of multiple fungal toxins were used to evaluate the acute and chronic dietary exposure risks of different genders of consumers. Results The estimated daily intake levels of alternariol and alternariol monomethyl ether in some Castanea mollissima samples were higher than 2.5 ng·kg^-1·bw·d^-1. The estimated daily intake levels of tentoxin and tenuzonic acid in all samples during the entire storage period did not exceed 1500 ng·kg^-1·bw·d^-1. The estimated daily intake/tolerable daily intak of nivalenol, fumonisin B₁, total fumonisin and zearalenone were all less than 100. The margin of exposure (MOE) was used to analyze the sterigmatocystin, and the result was greater than 10000. The 2 kinds of different chronic effects were analyzed for ochratoxin A. The cumulative risk assessment of mycotoxins in Castanea mollissima samples showed that some samples had MOE below 100 after storage for about 10 months. Conclusion All varieties of Castanea mollissima samples are no significant risk of mycotoxins to consumers after stored for 9 months in cold storage, and consumers can safely eat them. But multiple mycotoxins are detected simultaneously during the late stage of storage, which may pose health risks to humans. In order to clarify these health risks further, more toxicological data is needed.