The invention relates to a multilevel porous 
molecular sieve catalyst as well as a preparation method and application thereof. The preparation method of the multilevel porous 
molecular sieve catalyst comprises the following steps: adding an organic template agent 
ethanol solution into an aluminum source, a 
silicon source and a 
silane ethanol solution to form gel, performing 
air drying on the gel to obtain dry gel, adding water and tetrapropylammonium 
hydroxide into the dry gel to obtain a mixture, putting the mixture into a high-pressure kettle, crystallizing the mixture for 3 days at the temperature of 180 DEG C to obtain a multilevel porous ZSM-5 
molecular sieve, uniformly mixing the multilevel porous ZSM-5 molecular 
sieve with gamma-Al2O3, adding a dilute 
nitric acid solution, then performing mixed kneading, performing strip extruding for forming, 
drying and 
roasting in air so as to obtain a carrier; and soaking the carrier by utilizing a 
magnesium acetate solution, 
drying and 
roasting the carrier to obtain a phenylcarbinol 
alkylation catalyst. When the prepared catalyst is applied to the phenylcarbinol 
alkylation reaction, the catalyst has the advantages that 
coke and carbon are not easily generated, the activity is high, and the product selectivity is high. Compared with other catalysts in the prior art, for the catalyst disclosed by the invention, the activity and the reaction stability are high, and the service life is longer.