The fluid dynamics of the gas-liquid-liquid three-phase micro-dispersion process was studied in a double T-junction microchannel device.Two main flow patterns named "gas-in-oil-in-water coupled emulsion flow" and "bubble contained oil-water parallel flow" were observed and the effects of fluid feeding sequence

superficial velocity and confined microchannel on those flow patterns were discussed.A flow pattern map was established based on the experimental result to describe the flow pattern evolution.Mono-dispersed micro-bubbles with average volume ranging from 22 nl to 54 nl were controllably prepared together with the gas-in-oil coupled dispersed phase

whose average volume changed from 60 nl to 81 nl.Based on the Rayleigh-Plateau break-up mechanism of gas phase

mathematical equations were established to calculate the dispersed volumes of bubbles and coupled emulsions.