Early　gas　kick　detection　is　an　important　measure　to　ensure　well　control　safety.　In　accordance　with　the　fluctuation　of　the　bottomhole　pressure　during　early　gas　kick,　the　gas　kick　can　be　detected　rapidly　and　early　with　downhole　measurement　tool.　At　present,　erroneous　diagnosis　often　occurred　when　gas　kick　detection　was　performed　using　pressure　fluctuations　of　a　single　measured　point.　In　this　paper,　firstly,　considering　the　water　hammer　effect,　a　wellbore　pressure　fluctuation　model　at　the　initial　stage　of　gas　kick　was　established　to　accurately　describe　the　transient　annular　pressure　variations.　The　model　was　solved　using　the　composite　difference　scheme　and　was　verified　using　a　laboratory　gas　kick　experiment.　Secondly,　a　dual-measured-points　(DMP)　method　for　early　gas　kick　detection　was　presented　based　on　the　consistencies　and　discrepancies　of　bottomhole　pressures　at　two　measured　points.　The　distance　between　two　measured　points　was　optimized.　Simulation　results　indicated　that　the　annular　pressure　at　the　measured　point　increased　and　periodically　changed　with　time　in　the　initial　stage　of　gas　kick,　and　then　declined　approximately　linearly　after　the　gas-liquid　interface　reached　the　measured　point.　The　distance　between　the　two　measured　points　was　mainly　dominated　by　the　borehole　diameter,　and　increased　with　the　decrease　of　borehole　diameter.　The　gas　kick　confirmation　time　(GKCT)　obtained　using　DMP　method　was　2-7　min　and　the　corresponding　gas　kick　confirmation　volume　(GKCV)　was　0.3-0.5　m(3).　The　GKCT　diminished　with　the　increase　of　the　formation　permeability　and　bottomhole　negative　differential　pressure,　and　with　the　decrease　of　the　borehole　diameter　and　well　depth.