Using ordinary optical microscope technology, by comparing the granule shape and size of kudzu root starch, fern root starch, lotus root starch, lily starch, cassava starch, corn starch, sweet potato starch, potato starch, to identify the source and types of starch, solved the difficult problem of starch adulteration. This method is simple, less equipment investment, easy maintenance, low cost, batch testing, especially suitable for rapid supervision, inspection and a lot of starch samples for detection in business, facilitating the popularization.