This seems a bit troublesome, as I saw Mom do it when I was young.First, you need tosweet potatoescrushed, just like grindingsoy milk, then use a sieve to separate the residue, leaving only the liquid part. Let it sit for several days until the starch settles and solidifies. Dissolve the solidified starch with water.potato sheetsPrepare an iron plate, boil a pot of water, pour a thin layer of the diluted liquid on the iron plate, and place it over the boiling water to steam. Once the liquid turns clear, remove the iron plate from the hot water to cook the starch sheet thoroughly.sweet potato powderFinally, peel off the cooked sheets, let them cool halfway before cutting into strips, and then dry them to make sweet potato powder.