A simple method called low-temperature vacuum drying (LTVD) was used to produce a novel dehydrated potato flour called raw dehydrated potato flour (RDPF). Preparing RDPF by LTVD at 60°C, 70°C and 80°C in both slice and dice shape was investigated. Potato samples in dice shape are easier dehydrating than in slice shape, the starch granules of RDPF maintain ellipsoid shape as the native potato starch. The best temperature of LTVD to prepare the RDPF is around 70°C according to CIE chromaticity results. Dehydrate at 60°C in dice shape, 88.37% of the trypsin inhibitor activity of the fresh potato is maintained. The Mixolab curve shows that the RDPF has some similar rheological properties of the wheat flour. Protein undenatured, starch ungelatinized, with the high performance of processing properties, RDPF has a number of potential applications in the potato staple food manufacture.