In order to study the problem that the flow in the internal channel of the microfluidic chip is different from that of the macroscopic system by the FD numerical simulation image imaging technology. Taking the liquid-liquid extraction of microfluidic chip as the research object, this paper analyzes the theoretical basis, working principle, structural parameters, and the influence of working parameters on the fluid flow of liquid-liquid extraction. The results are as follows: when the inlet velocity of flowing liquid is 10^(−5) m/s, the diffusion efficiency can still be maintained at 95%; the double ψ-type aqueous phase showed laminar flow, the two-phase contact interface increased compared with the bottom flow rate, and the extraction efficiency increased to 98%; the extraction efficiency of double ψ type is higher than that of double Y-type: when the flow velocity ratio increases from v a q : v oil = 1 : 2 to v a q : v oil = 5 : 1 , the extraction efficiency increases to 99.8%; the experimental extraction efficiency is compared with the diffusion efficiency simulated by simulation. The diffusion efficiency of the cross type is 1.05 times that of the extraction efficiency, and that of the cylindrical type is 1.04 times that of the extraction efficiency. In this study, CFD is used to simulate the characteristics of droplet microfluidic multiphase flow, which enriches the theoretical method and research experience of liquid-liquid laminar flow.