Surface　roughness　is　an　important　indicator　in　the　evaluation　of　machining　and　product　quality,　as　well　as　a　direct　factor　affecting　the　performance　of　components.　A　rapidly　developing　filtering　technology　has　become　the　main　means　of　extracting　surface　roughness.　The　International　Organization　for　Standardization　(ISO)　is　constantly　updating　and　improving　the　standard　system　for　filtering　technology　in　order　to　meet　the　requirements　of　technological　development.　Based　on　the　filters　already　accepted　by　the　international　standard　ISO　16610,　this　study　briefly　introduces　the　filtering　principle　of　each　filter,　reviews　the　development　of　each　filter　in　the　application　of　surface　roughness,　and　compares　the　advantages　and　limitations　of　their　individual　performances.　The　application　range　of　each　filter　is　summarized　and,　finally,　the　future　direction　of　the　digital　filtering　used　in　surface　roughness　is　extrapolated.