A high-speed camera observation system was used to perform a full flow field flow display experiment on circular microchannel structures with different diameter structures.The flow morphology of multiphase flow was analyzed by controlling variables,such as gravity influence,gas-liquid flow ratio and flow direction;on the basis of this,the flow characteristics of gas-liquid multiphase flow along the flow channel such as pressure and velocity field were obtained.The results show that the microchannel structure will significantly affect the flow pattern of gas-liquid multiphase flow,the complex structure of microchannels intensifies the fluid shear flow characteristics and greatly promotes the mixing effect of gas-liquid two-phase flow.