The invention discloses a method for preparing a multi-level-structured molecular sieve by taking a mesoporous material as an indirect template agent. The method comprises the following steps: mixing aluminum oxide spheres or silicon oxide microspheres, an external silicon source or an aluminum source, phosphoric acid, a template agent and water to form a crystallization raw solution; transferring the uniformly mixed crystallization raw solution into a hydrothermal kettle taking tetrafluoroethylene as a lining, and ageing; after ageing, putting the hydrothermal kettle into a homogeneous reactor for crystallization; cooling a crystallized solution, taking out the crystallized solution and carrying out washing and centrifuging treatment; filtering an obtained solid-liquid mixture, washing and drying; and roasting to remove the template agent to obtain the multi-level-structured molecular sieve. The molecular sieve comprises mesopores and micropores; generation and diffusion of isobutylene in pore channels can be inhibited very well; isomeric hydrocarbon and aromatic hydrocarbon, which have relatively great molecules, can be subjected to more serious diffusion limitation; and meanwhile, the diffusion resistance of a target product, low-carbon olefin, particularly propylene, is reduced due to the presence of the mesopores, so that the prepared multi-level-structured molecular sieve is used as a catalyst, is not easy to inactivate and has good stability.