Emulsification　is　a　crucial　technique　for　mixing　immiscible　liquids　into　droplets　in　numerous　areas　ranging　from　food　to　medicine　to　chemical　synthesis.　Commercial　emulsification　methods　are　promising　for　high　production,　but　suffer　from　high　energy　input.　Here,　we　report　a　very　simple　and　scalable　emulsification　method　that　employs　the　drag-reducing　liquid　gating　structure　to　create　a　smooth　liquid-liquid　interface　for　the　reduction　of　resistance　and　tunable　generation　of　droplets　with　good　uniformity.　Theoretical　modeling　and　experimental　results　demonstrate　that　our　method　exhibits　ultrahigh　efficiency,　which　can　reach　up　to　more　than　4　orders　of　magnitude　greater　energy-saving　compared　to　commercial　methods.　For　temperature-　sensitive　biological　components,　such　as　enzymes,　proteins,　and　bacteria,　it　can　offer　a　comfortable　environment　to　avoid　exposure　to　high　temperatures　during　emulsifying,　and　the　interface　also　enables　the　suppression　of　fouling.　This　unique　drag-reducing　liquid　gating　interfacial　emulsification　mechanism　promotes　the　efficiency　of　droplet　generation　and　provides　fresh　insight　into　the　innovation　of　emulsifications　that　can　be　applied　in　many　fields,　including　the　food　industry,　the　daily　chemical　industry,　biomedicine,　material　fabrication,　the　petrochemical　industry,　and　beyond.