Wash the lotus root thoroughly, peel, and slice thinly.
Add a little vinegar to boiling water, blanch the lotus root for 1 minute, then rinse in cold water.
In a pot, combine vinegar, sugar, salt, and water to make the pickling sauce. Bring to a boil.
Place the blanched lotus root in a container and pour the hot pickling sauce over it.
Let it cool completely, cover with a lid, and refrigerate for at least 2 hours.