According　to　the　characteristics　of　normalized　pressure　drop　along　the　riser　and　the　riser　outlet　liquid　holdup,　flow　patterns　that　occurred　within　a　pipeline-riser　system　was　discriminated　and　classified　into　five　categories-SS1,　SS2,　SS3,　OSC　and　STB.　Manual　control,　PID　control　based　on　riser　base　pressure　and　PID　control　based　on　riser　pressure　drop　were　carried　out　to　eliminate　the　observed　SSI　in　order　to　stabilized　the　periodic　pressure　and　flow　rates　oscillations.　The　average　values　of　riser　bottom　pressure,　riser　pressure　drop　and　inlet　liquid　flow　rates　as　well　as　the　valve　opening　after　severe　slugging　being　stabilized　by　above-mentioned　three　control　methods　were　compared　to　evaluate　the　control　effects.　The　results　show　that　the　PID　control　strategy　based　on　riser　pressure　drop　presents　the　best　performance　with　the　largest　valve　opening　and　a　relative　high　inlet　flow　rate,　the　PID　control　strategy　based　on　riser　base　pressure　takes　the　second　place　and　the　manual　control　shows　the　worst.　©　2016,　Science　Press.　All　right　reserved.