The invention relates to the field of fine chemical engineering and particularly provides a method for preparing propylene glycol monomethyl ether. The method comprises steps as follows: epoxypropane and methanol are contacted with a catalyst under the condition of an alcoholysis reaction, wherein the catalyst comprises an aluminosilicate molecular sieve, the aluminosilicate molecular sieve comprises elements of Al, Si and O; the pore volume of the aluminosilicate molecular sieve is 0.3 cm<3>/g or higher, the total surface area is 200 m<2>/g or larger, the external surface area is 30 m<2>/g or larger, and the external surface area accounts for 10%-55% of the total surface area; the measured benzene adsorption amount of the aluminosilicate molecular sieve is at least 65 mg/g molecular sieve under the conditions that the temperature is 25 DEG C, P/P0 is equal to 0.10, and adsorption time is 1 h, and N2 has micropore size distribution ranging from 0.9 nm to 2.0 nm under the static adsorption test. With the adoption of the method, the epoxypropane conversion rate and the propylene glycol monomethyl ether selectivity are high.