Abstract: 2,6-Diisopropylnaphthalene （2,6-DIPN） is a crucial intermediate for the synthesis of high-performance polymers such as polyethylene naphthalate （PEN）. However, its efficient shape-selective synthesis remains challenging due to diffusion limitations and catalyst deactivation caused by coke deposition. To improve the selectivity and catalytic stability for 2,6-DIPN synthesis, a series of hierarchical MOR zeolites were prepared via a hydrothermal method using cetyltrimethylammonium bromide （CTAB） to introduce secondary mesopore. The influence of CTAB addition on the crystal structure, textural properties, acidity, and catalytic performance in naphthalene isopropylation was systematically investigated. The results demonstrate that an appropriate amount of CTAB generates a well-developed mesoporous network while preserving the integrity of the MOR framework, concurrently increasing the number of accessible Brønsted acid sites associated with the 12-MR channels. Notably, the MOR-3 sample, exhibiting the highest specific surface area （556.2 m²/g） and mesopore volume （0.34 cm³/g）, achieved the best overall catalytic performance in the isopropylation of naphthalene with isopropanol: a naphthalene conversion of 84.2%, a diisopropylnaphthalene （DIPN） selectivity of 43.8%, a 2,6-DIPN selectivity within DIPN of 68.2%, a 2,6-DIPN yield of approximately 25.2%, and the lowest coke content （9.5 wt.%）. Combined analyses from thermogravimetry, Raman spectroscopy, and GC-MS of soluble coke species suggest that the hierarchical pore architecture facilitates mass transfer, reducing the residence time of intermediates near acid sites, thereby suppressing the formation of polyalkylated naphthalene precursors and subsequent coke deposition. The results suggest that CTAB can effectively regulate the MOR zeolite to construct a hierarchical pore structure, thereby preserving its shape-selective properties while significantly improving mass transfer and coke resistance, and providing a feasible catalyst design strategy for the highly selective synthesis of 2,6-DIPN.