The invention provides a synthesis method of an integral hierarchical-pore ZSM-5 molecular sieve. The synthesis method comprises the following steps that 1, an aluminum source, sodium hydroxide, an organic template agent and deionized water are added to a beaker (1) to be mixed evenly, then a silicon source is gradually added to the beaker, intense stirring is performed to form homogeneous gel, and the homogeneous gel is poured into a stainless steel reaction kettle with a polytetrafluoroethylene liner and is crystallized at the temperature of 100-220 DEG C for 1-7 days; 2, the product obtained in the step 1 is repeatedly washed with the deionized water till a pH value is approximately neutral, and drying is performed at the temperature of 90-110 DEG C to obtain a ZSM-5 molecular sieve; 3, the ZSM-5 molecular sieve is roasted, and the organic template agent is removed to obtain the integral hierarchical-pore ZSM-5 molecular sieve. The steps of an existing integral hierarchical-pore catalyst preparation technology are simplified, expensive auxiliary materials such as structure guiding agents and special integral carriers are not needed, and the preparation cost is reduced.