Inspired by the effect of mesh segmentation, a novel planar mesh segmentation microchannel device (PMSM) was developed to investigate the extraction efficiency of Mg (Ⅱ) from liquid-liquid and gas-liquid-liquid extraction by utilizing the segmented flow and segmentation effect of metal mesh, as well as the continuous and multi-stage process. When O/A = 1 and total flow rate Q = 4 mL/min, the extraction equilibrium value was reached in only 79.5 s, while conventional stirred extraction required 300 s. When aqueous phase residence time was kept constant and Q g = 2.5 mL/min, the maximum extraction efficiency of 31.04% was achieved in only 26.5s, which exceeded the equilibrium value of the conventional one-stage extraction. In addition, the flow patterns, total volume mass transfer coefficient (K La), extraction kinetics and the correlation diagram of We aq-We o-g-E were used to further reveal the mechanism of mass transfer enhancement.