The work aims to study the effects of modified atmosphere packaging combined with ClO2 on delaying the yellowing and decay of fresh-cut broccoli under cold storage conditions, so as to maintain the nutritional quality of fresh-cut broccoli. Fresh-cut broccoli was used as experimental material, and four treatments were set up:CK, modified atmosphere packaging, 0.5 g-ClO2 and modified atmosphere packaging+0.5 g-ClO2. The quality index, antioxidant index and microbial index of fresh-cut broccoli stored at 4 °C were compared. Compared with the single use of modified atmosphere packaging and 0.5 g-ClO2 treatment, the combination of them could significantly reduce the weight loss rate, decay rate, relative conductivity, malondialdehyde, O2–., H2O2 content and total number of colonies of fresh-cut broccoli, maintain a higher level of soluble solids, chlorophyll content and antioxidant enzyme activity, maintain cellmembrane integrity, delay the phenomenon of chlorosis and yellowing, and improve the antioxidant capacity. It can most effectively maintain the storage quality of fresh-cut broccoli. At 4 °C, the use of modified atmosphere packaging+0.5 g-ClO2 treatment can significantly inhibit the loss of nutrients in fresh-cut broccoli, improve its oxidation resistance, and prolong its storage period. The preservation period can be extended to 20 days, maintaining good application value. It has good economy and feasibility.