A method for directly preparing an empty shell type small grain ZSM-5 molecular sieve. The method comprises: uniformly mixing and stirring an organic template agent, a silicon source and water; dripping an aqueous solution of an aluminum source into the mixture; preserving room temperature, and continuously stirring for a period of time; and performing hydrothermal crystallization, and washing, drying and roasting the obtained product to obtain the Molecular sieve. The molecular sieve has high degree of crystallinity and uniform particle size. Moreover, the method requires short time, simple operation and only one step, no extra surfactant is needed, and secondary acid and alkali treatment is not needed.