1. Thaw first: Most of the hairtail bought in the mall is frozen hairtail, so it should be thawed first. Put hairtail in a plastic bag, and then soak it in warm water below 75 degrees Celsius for 1-3 hours. You can also put it in the freezer and thaw it for about half a day.

2. Wash the viscera and gills: after thawing, cut the belly of hairtail with a knife or clean scissors, take out the viscera inside and discard it. If there is caviar, throw it away together, because it is not clean. If there is a fish head, remove the gills.

3. Finally, rinse the hairtail inside and outside with clear water.