The invention relates to an SAPO-34 / ZSM-5 composite
molecular sieve and a synthesis method of the composite
molecular sieve, solving the problems of single
pore diameter, low acidity and low reaction activity of the porous materials which are synthesized by the prior art. The synthesis method of the composite
molecular sieve comprises the following steps: firstly mixing a
silicon source, an aluminum source, a
phosphorus source and an organic template agent according to a certain ratio, then adding a certain quantity of ZSM-5 molecular sieves, uniformly mixing and carrying out hydrothermal
crystallization, and synthesizing the SAPO-34 / ZSM-5 composite molecular
sieve by controlling
nucleation and
crystal growth conditions, wherein the composite
molecular size is adjustable in ratio of two phases; an XRD
diffraction spectrum of the composite
molecular size has a maximum d interval at the positions of 7.92+ / -0.1, 8.79+ / -0.1, 9.52+ / -0.1, 12.85+ / -0.1, 16.00+ / -0.1, 20.56+ / -0.1, 23.01+ / -0.05, 23.24+ / -0.05, 23.86+ / -0.05, 25.83+ / -0.1, 30.55+ / -0.1 and 31.32+ / -0.1. The composite molecular
sieve can be applied to industrial production for preparing
aromatic hydrocarbon by reacting methyl
alcohol /
dimethyl ether.