Through　constructing　the　digital　model　of　a　two-stage　CNG　regulator　to　simulate　the　working　performances,　8　factors　possibly　affecting　the　pressure　stability　of　regulator＇s　outlet　were　deliberately　drawn　out.　Then,　by　the　method　of　DOE,　sensitivity　of　the　parameters　were　analyzed,　and　the　most　sensitive　3　parameters　were　figured　out　to　make　improvements　of　the　regulator.　Consequently,　comparative　experiments　for　the　4　different　regulators　were　conducted　based　on　professional　test　platform.　The　experimental　results　reveal　that　the　flow　stability　for　the　regulators　with　improvements　is　increased　by　25%　and　50%　respectively　under　low　flow　conditions　and　high　flow　conditions,　and　the　pressure　stability　of　outlet　is　increased　by　respectively　80%　and　77.8%　simultaneously.　©　2019,　China　Mechanical　Engineering　Magazine　Office.　All　right　reserved.