Abstract: Light olefins such as ethylene and propylene, as raw materials for synthesizing polymer materials, play a crucial role in promoting industrial and agricultural development and improving people's living standards. In this study, a series of ZSM-5 zeolites with short b-axis were synthesized using urea and tetrapropylammonium hydroxide （TPAOH） as structure-directing agents, aiming to reduce diffusion limitations and enhance the selectivity of light olefins in the catalytic cracking of plastics. The effects of the amount of urea and the silica-alumina ratio on the b-axis thickness were investigated. Further catalytic cracking experiments on high-density polyethylene were conducted to examine the structure-activity relationship of the zeolites. The experimental results demonstrated that by adjusting the amount of urea added, sheet-like ZSM-5 zeolites with b-axis thicknesses ranging from 197 to 668 nm could be obtained, achieving precise control over the b-axis dimension. Among them, the short b-axis Z5-50-1.0U zeolite, with a silica-alumina ratio of 50, n（TPAOH/SiO₂）=0.34, and n（Urea/SiO₂）=1.0, exhibited superior selectivity for light olefins in the reaction. The yields of liquid and gas products were 20.4% and 78.4%, respectively, with selectivities for BTEX and light olefins reaching 69.8% and 56.8%.