To soybean oil as the main raw material, chicken for the fried food. The effects of different frying time, frying temperature and the quality of each batch of fried chicken on the quality of soybean oil were studied by measuring the physical and chemical indexes, including color, acid value, peroxide value, carbonyl valence price and polar component of soybean oil. Moreover, the low-frequency nuclear magnetic resonance imaging (MRI) technology was used to verify the physical and chemical indicators. The results showed that the color, acid and carbonyl value of the frying oil increased with the frying time, temperature and the amount per batch; the peroxide value increased rapidly with the frying time, and then decreased slowly; the number of frying batches also increased with the frying temperature. According to the MRI comparison method, with the prolongation of the frying time, the dark red proton accumulation, dense flocculation, blurred edge, and liquid fluidity deviation were observed.