The work aims to investigate the effects of electron beam and γ-ray on the fat oxidation and mold content of oil plants. Peanut, sesame and soybean were irradiated with 1, 3, 5, 7, 9 kGy irradiation dose. The effects of different rays and different irradiation dose on oil content, acid value, peroxide value and total mold number were analyzed. Irradiation basically had no effect on the oil content of oil plants. Two kinds of irradiation could effectively reduce the acid value of peanut, sesame and soybean, and the change law was similar. The acid value of peanut, sesame and soybean was the lowest at 5 kGy electron beam irradiation dose, which was reduced by 54.29%, 37.50% and 37.33%, respectively. The decrease of acid value of peanut and sesame irradiated by γ ray was greater than that by electron beam irradiation, but that of soybean was the opposite. The two kinds of radiation had little effect on the peroxide value of peanut, but the peroxide value of γ-ray irradiation was slightly lower than that of electron beam irradiation. The two kinds of ray irradiation increased the peroxide value of sesame to some extent. With the increase of the dose of the two kinds of radiation, the peroxide value of soybean decreased. At the dose of 1~5 kGy, the reduction of peroxide value of soybean irradiated by γ rays was lower than that irradiated by electron beam. Irradiation could effectively kill the mold in the oil plants; moreover, the larger the irradiation dose, the better the bactericidal effect. In contrast, the γ-ray irradiation had better killing effect on the mold of oil plants than the electron beam irradiation. The irradiation dosage of 3 kGy of the two kinds of rays has no significantly negative impact on the quality of the oil plants, and can be used as a suitable dose for pest control and mold prevention of oil plants.