The invention relates to a method for preparing a molecular sieve, aiming to provide a method for synthesizing a molecular sieve under a solvent-free condition through grinding solid phase raw materials. The method comprises the following steps of: grinding and mixing the pre-weighed solid raw materials which include silicon sources, metal atom sources, an organic template agent, and an alkalinity regulator, putting the grinded material into a reactor, and performing a crystallization reaction for 1-8 days at a temperature ranged from 80 DEG C to 180 DEG C; and drying for over 12 hours at a temperature of 80 DEG C after washing the reaction product thoroughly by using deionized water to obtain a final product. A ZSM-5 molecular sieve, a Beta molecular sieve, a ZSM-39 molecular sieve, and a SOD molecular sieve, which have a good crystallinity and a controllable silicon-aluminum ratio, can be prepared through the method provided by the invention. The synthetic route only involves a mixture of the raw materials without a use of any solvents, which simplifies the synthetic process compared to the traditional method, improves the yield rate and the single reactor utilization rate greatly, reduces the production cost greatly, saves energy and reduces emission, and has a wide industrial application prospect.