The invention discloses a method for preparing 1-chloro-2-methyl-2-propanol. The method disclosed by the invention is characterized by comprising the following preparation steps: filling cation exchange resins into a filling pipe, wherein the length of the filling pipe filled with the cation exchange resins is 0.1-100 meters and the diameter of the filling pipe is 0.1-0.5 meter; respectively adding a reaction raw material, namely 2-methyl-3-chloropropene and water to the filling pipe from two feed ports of the filling pipe; cooling the exterior of the filling pipe to 0-45 DEG C, wherein the flow rate of the 2-methyl-3-chloropropene is 0.5-20kg/h and the flow rate of the water is 1-100L/h; and receiving a reaction liquid which flows out of the pipe. The preparation method disclosed by the invention has the advantages that a reaction is completed in one step; the production cost is low; a large quantity of acid waste water is not generated; and the pollution and damage to an environment are reduced.