The invention provides a catalysis conversion method used for producing more propylene and making arene at the same time; the hydrocarbon raw material with different cracking performances contacts catalytic cracking catalyst, so as to carry out the cracking reaction inside a fluidized bed reactor under the conditions of 450-750 DEG C of temperature, 0.1-800h<-1> of weight hourly space velocity, 0.10-1.0MPa of pressure, 1-150 of weight ratio of catalyst to raw material and 0.05-1.0 of weight ratio of water vapour to raw material; spent catalyst and reaction oil gas are separated, and the spent catalyst is returned to the reactor after regeneration; the reaction oil gas is separated so as to gain the object outcome: low carbon alkene, arene and re-cracked raw material. The method produces low-carbon alkene such as propylene, and the like, from the heavy raw material to the most extent; wherein, the yield of the propylene is more than 40% by weight; meanwhile, arene such as toluene, dimethylbenzene and the like can be generated at the same time; unexpectedly, the reduction range of the dry gas yield achieves more than 80% by weight.