The invention discloses a microreactor including a reaction channel; at least two eight-trigram fish-shaped reaction chambers are sequentially arranged on the reaction channel; a first shunting columnand a second shunting column are arranged in the first reaction chamber and the second reaction chamber respectively, fluid radially jetted through an inlet of the first reaction chamber is divided into two branches by the first shunting column, and the two branches are combined in the middle of the first reaction chamber and then sprayed at an outlet of the first reaction chamber; the fluid jetted through the inlet of the second reaction chamber is divided into two branches by the second shunting column, and the two branches are combined in the middle of the reaction chamber and are jetted at the outlet. According to the micro-reactor, high pressure drop generated by friction between high-speed fluid and the wall surface is avoided. The high-speed collision between the high-speed fluid and the shunting columns accelerates the crushing of the fluid and divides the jetted fluid into two parts to reduce the diffusion distance of the fluid, so that a relatively high mixing effect is achieved under low pressure drop, the coalescence of multi-phase fluid caused by eddy current is avoided, and the microreactor is particularly suitable for mixing and mass transfer of the multi-phase fluid.