NOVELTY - Synthesizing heteroatom zeolite socony mobil-5 (ZSM-5) molecule sieve comprises (i) adding gallium source and aluminum source into organic template, then adding sodium hydroxide and mixing with silicon source to forming sol-gel system; (ii) crystallizing the sol-gel system to obtain molecular sieve powder; (iii) washing the molecular sieve powder, filtering and drying, and calcining for 4-8 hours at 500-600 degrees C to remove the organic template; and (iv) subjecting the resulting molecular sieve powder into ion exchange using ammonium hydroxide solution, drying and calcining.    USE - The hydrogen type heteroatom ZSM-5 molecule sieve is useful for preparing liquid fuel and liquefied petroleum gas by catalytic fast pyrolysis (claimed).    ADVANTAGE - The method utilizes raw materials of low cost, ensures adjustment of molecular sieve pore size, and does not produce impurity in crystal phase system. The molecule sieve belongs to MFI structure molecule sieve, increases total yield of monocyclic aromatic hydrocarbons including benzene, toluene and xylene in catalytic fast pyrolysis of biomass and polyethylene, and increases selectively to more than 80%.    DETAILED DESCRIPTION - Synthesizing heteroatom zeolite socony mobil-5 (ZSM-5) molecule sieve comprises (i) taking ethyl orthosilicate, silicic acid, sodium silicate and/or silica sol as silicon source, taking aluminum sulfate, pseudoboehmite, aluminum isopropoxide and/or aluminum hydroxide as aluminum source, taking gallium sulfate or gallium nitrate as gallium source, taking sodium chloride or sodium hydroxide as mineralizing agent, and taking tetrapropylammonium hydroxide as organic template, where the molar ratio of silicon dioxide, aluminum oxide, gallium(III) oxide, sodium hydroxide, tetrapropylammonium hydroxide and water is 25:x:y:1:(3-10):(1000-3000), x+y is 0.5-3 and x/y is 0-5, adding gallium source and aluminum source into organic template, then adding sodium hydroxide and mixing with silicon source to forming sol-gel system; (ii) crystallizing the sol-gel system at 160-200 degrees C for 48-80 hours to obtain molecular sieve powder; (iii) washing the molecular sieve powder, filtering and drying, and calcining for 4-8 hours at 500-600 degrees C to remove the organic template; and (iv) subjecting the resulting molecular sieve powder into ion exchange using ammonium hydroxide solution, drying in an oven at 110 degrees C and calcining for 4-8 hours at 500-600 degrees C to obtain hydrogen type heteroatom ZSM-5 molecule sieve. INDEPENDENT CLAIMS are also included for:    (1) the hydrogen type heteroatom ZSM-5 molecule sieve, prepared by the above method; and    (2) use method of the hydrogen type heteroatom ZSM-5 molecule sieve in preparing liquid fuel and liquefied petroleum gas by catalytic fast pyrolysis, where the catalytic fast pyrolysis raw material is lignocellulosic biomass and/or waste plastic, the catalytic fast pyrolysis utilizes hydrogen type heteroatom ZSM-5 molecule sieve as catalyst and the catalytic fast pyrolysis main product comprises aromatic hydrocarbon and liquefied petroleum gas.