The　compressor　is　a　key　component　of　the　integrated　electricity　and　gas　systems.　The　position　of　its　operational　point　within　the　operational　domain　significantly　impacts　the　safe　and　stable　functioning　of　the　entire　system.　Meanwhile,　its　model　non-convexity　significantly　increases　the　difficulty　of　solving　the　optimal　power-gas　flow.　A　dynamic　optimal　power-gas　flow　convexification　algorithm　considering　the　operation　domain　is　proposed　based　on　the　accurate　compressor　modeling　and　different　transmission　characteristics　of　the　power　and　natural　gas　systems.　First,　a　3D　compressor　operation　domain　model　is　constructed　based　on　the　mapping　relationship　between　the　operating　parameters　and　the　state　variables,　and　the　convex　envelope　relaxation　of　the　operation　domain　is　realized　through　the　hyperplanes.　Then,　a　dynamic　optimal　power-gas　flow　model　considering　the　different　transmission　characteristics　is　developed,　a　mixed　integer　second-order　cone　convex　reformulation　of　the　model　is　realized,　and　a　convexification　algorithm　based　on　dynamic　linearization　and　tightening　convex　envelope　is　proposed.　Finally,　results　demonstrate　the　effectiveness　of　the　proposed　model,　indicating　that　the　proposed　algorithm　outperforms　the　sequential　cone　programming　algorithm　in　both　computational　accuracy　and　efficiency.　©2024　Chin.Soc.for　Elec.Eng.