Wash the wild dropwort thoroughly and drain the water.
Blanch the wild dropwort briefly in boiling water, then rinse in cold water.
In a pot, combine soy sauce, water, vinegar, sugar, and salt. Bring to a boil to make the pickling brine.
Place the blanched wild dropwort into the cooled pickling brine.
Let it mature at room temperature for a day, then store in the refrigerator.