UOS format, also known as Uniform Office Format or Unified Office Format is used by some Chinese variants of OpenOffice / OpenDocument formats. Users often struggle with the export of these files.
According to some sources, they are just renamed OpenDocument files, and renaming the suffix might be sufficient, but some tools list these formats in separate categories.
You can try to use OpenOffice.org or LibreOffice to open these files for example, but if this fails you might need to check out for the original, Chinese software to export the files or data to standard format.
Updated: February 16, 2024