The natural bentonite and modified sodium bentonite of Gaomiaozi (GMZ) were investigated, and the swelling capacity of samples after electron irradiation-thermal sequential aging and γ-ray irradiation-thermal sequential aging were analyzed by XRD. The results show that the influences of two different irradiation-heat aging modes on swelling capacity of GMZ bentonite are weak. The bentonite can maintain its original swelling capacity after the aging process.Cited