The invention discloses a microfluidic double-water-phase cocurrent laminar flow enzymatic reaction technique. By using the double-water-phase solution as the carrier, enzymatic reaction separation is performed in a double-Y-shaped microfluidic device, an injection pump is used for providing flow powder for the fluid, and an injector needle and a glass sheet are used for preparing a minitype device, thereby constructing a double-water-phase cocurrent laminar flow mass transfer interface; and thus, the enzymatic reaction can be performed quickly and continuously, and the product can be separated and purified. The device has the advantages of simple structure and the like, and is convenient to manufacture. The technique has better separating effect than the traditional batch-type double-water-phase biological reaction, has the advantages of continuous operational process, low energy consumption and flexible control on the laminar flow interface, and can continuously and circularly use the enzyme solution to save the cost. The microscale double-water-phase laminar flow interface is utilized to reinforce the interphase mass transfer, enzymatic reaction and separation, and thus, the technique has wide application prospects in the field of biological reaction separation with expensive raw materials and high product added value.