The invention discloses a method for preparing a meso-microporous composite Y molecular sieve. According to the method, oligomerization phenolic resin serves as a template agent, and the molecular sieve is prepared through a hydrothermal crystallization method. The method includes the specific steps that a silicon source and an aluminum source are mixed, stands for aging for 2-72 hours at the temperature of 5-60 DEG C to prepare a guiding agent; the silicon source, the guiding agent, the aluminum source and the oligomerization phenolic resin are mixed to prepare gel, the molar ratio of the components of Na2O, Al2O3, SiO2, H2O and oligomerization phenolic resin in the reaction mixture gel is 0.5-10:1:5-40:80-800:0.2-8; the reaction mixture is crystallized in the static mode, crystallization temperature ranges from 90 DEG C to 150 DEG C, and crystallization time ranges from 6 hours to 72 hours; the reaction mixture is filtered, washed, dried and calcined, calcination temperature ranges from 400 DEG C to 700 DEG C, and calcination time ranges from 2 hours to 12 hours. The relative crystallinity of the obtained composite Y molecular sieve is larger than 85%, and the mesoporous aperture ranges from 4 nm to 10 nm. The preparation method is low in production cost, free of environment pollution and good in industrial application prospect.