The invention provides a method for synthesizing methionine hydroxy analogue by continuous and rapid hydrolysis of 2-hydroxy-4-methylthio butyronitrile. The method comprises the following steps: feeding acid and 2-hydroxy-4-methylthio butyronitrile into a microchannel reactor loading a solid catalyst for reaction, controlling the reaction temperature to be 80 to 130 DEG C and the pressure to be 0.1 to 0.5MPa, ensuring that the residence time of a reactant in a micro channel is 1 to 10min, adding water into the mixed liquid flowing out from the microchannel reactor, continuously hydrolyzing for20 to 60min, and ensuring that the reaction temperature to be 100 to 140DEG C and the reaction pressure to be 0.1 to 0.6MPa to obtain the methionine hydroxy analogue and a small amount of a byproduct, namely ammonium sulfate. By adopting the method, continuous and rapid preparation of the methionine hydroxy analogue is reazlied, the traditional intermittent tower device is avoided, the use of inorganic acid of 50 percent is reduced, no ammonium hydroxide is needed for neutralization, no organic solvent is used, and cleaness, environmental protection and sustainability are achieved; the acidolysis time of 2-hydroxy-4-methylthio butyronitrile is greatly reduced, pyrolysis polymerization of raw materials and production of by-products are reduced, and the product quality and yield are improved.