The invention discloses a method for fast synthesizing ZSM-5 molecular sieves. The method comprises the synthesis steps that (1) firstly, aluminum sources, silicon sources, template agents, water and alkali are uniformly mixed according to the following mol ratios: SiO2/Al2O3 equals to 10 to 60, OH<->/SiO2 equals to 0.1 to 0.8, R/SiO2 equals to 0 to 0.2, and H2O/SiO2 equals to 10 to 200, then, the stirring aging is carried out for 2 to 4 hours, and aged sol-gel is obtained, wherein R is template agents; (2) the aged sol-gel is baked into dry glue under the condition being 60 to 90 DEG C, and then, the dry glue is ground into powder dry glue powder; (3) the dry glue powder is placed into a reaction kettle with a polytetrafluoroethylene inner liner, water is added, and the static crystallization is carried out for 12 to 40 hours under the condition being 150 to 180 DEG C; (4) the crystallization products are taken out to be washed by water and baked, then, the temperature is raised to 450 to 650 DEG C, and the products are roasted for 4 to 6 hours to obtain the ZSM-5 molecular sieves. The method has the advantages that the supersaturation degree of the sol-gel system can be enhanced when the sol-gel is baked into dry glue so that the system fast forms crystal nucleus, and the ZSM-5 zeolite molecular sieves are fast synthesized. The method has the characteristics that the simplicity is realized, the time is saved, the cost is low, and the pollution is low.