1. Choose a suitable harvest time. Onions should be harvested when the leaves near the ground are yellow, the pseudostems are lodging, and the bulb epidermis is dry and presents a unique color.

2. The harvested onions should be fully aired in the sunny place with ventilation, and the onions with mechanical damage, pests and diseases and stunted growth should be removed, and the fake stems should be removed for storage.

3. Before the onion is put into storage, thoroughly clean the warehouse and fumigate it with warehouse fumigant. First put the disinfectant into the warehouse at several points, light a cigarette with a match and smoke a lot, then close the doors and windows for 4 hours.

4. Before the onion is put into storage, the storage temperature should be reduced to about MINUS one degree Celsius, and the daily storage capacity should not be too much. When stacking, ventilation pipes should be left.