Vermicelli is a traditional food in China, which is made from sweet potato and potato by pulping and precipitation. Production methods are divided into manual method and mechanical method. Hand-made products include selecting materials, taking powder, thickening ingredients, adding alum to mix flour, leaking boiling water, drying in cold water bath and packaging. Mechanized processing includes starch raw materials → paste making → kneading → vacuumizing → silk leakage molding → cooking and gelatinization → cooling and powder fishing → cutting and hanging → condensation → freezing → thawing and drying → packaging. Whether it is hand-made or machine-made, it needs a series of steps and processes to ensure the quality and taste of the products.