1. Freeze fresh asparagus completely at low temperature, then vacuum the frozen asparagus, directly evaporate the frozen water in the asparagus, dry the asparagus and seal it.

2. After the asparagus is cooked, put it in the frozen layer of the refrigerator for preservation, so that the asparagus will be preserved for a longer time, and if it is well preserved, it can be as long as 1 month.