The invention provides a RSS data flatting method based on a multi-dimension analysis algorithm, which aims at solving the defects of reducing Radio Map precision and locating precision greatly caused by the reduced RSS data collection, environment noise and increased influence of the collection error on Radio Map in the prior art. The specific process is as follows: 1. arranging m AP in the indoor area to be located, 2. obtaining similarity distance dik and djk, 3. obtaining similarity matrix among different RP, 4. obtaining the similarity distance of noise RP and other RP, replacing the corresponding value in the similarity matrix on the data space in step 3, 5. calculating and obtaining RSS', replacing RSS in step 1; and 6, repeating step 4 and step 5 to realize flatting the RSS data. The flatting method provided in the invention is used for locating indoor area.