Synthesis method and application of composite pore zeolite beta

The invention provides a hydrothermal synthesis method of composite pore zeolite beta. In a hydrothermal crystallization process, a polymerized compound containing a dissociable polydiallyldimethylammonium (PDADMA) cation as a template, wherein a consumption mole ratio of a silicon source by SiO2 to the polymerized compound by the PDADMA cation monomer, SiO2/PDADMA is 1-10, preferably 3-8, and most preferably 5-7, a molar ratio of the silicon source by SiO2 to an alkaline source by an alkali metal oxide M2O, SiO2/M2O, is 1-10, preferably 3-8, and most preferably 4-6, the temperature is 150-230DEG C, and preferably 170-200DEG C, and the hydrothermal crystallization process lasts for 48-312h, preferably 60-240h, and most preferably 72-120h. The invention also provides a use of the synthesized composite pore zeolite beta in hydrocarbon conversion catalysts.