Police charged the 22 activists with violating the Communicable Diseases Act by holding a demonstration against the earlier arrest of two student protest leaders.
A crowd of demonstrators turned up to offer moral support to the 22 activists as riot police guarded the station.
Other prominent protesters charged included Panusaya “Rung” Sithijirawattanakul and Chaiamorn “Ammay” Kaewwiboonpan.