In this study, Sn-based catalysts supported on Silicalite-1 were prepared via the impregnation method, and CuSn alloys were constructed by introducing Cu components for propane dehydrogenation (PDH). Using characterization techniques such as XRD, H₂-TPR, XPS, and Py-IR, the effects of Sn loading and Cu/Sn molar ratio on the PDH performance of the catalysts were systematically investigated. The results showed that the highest propylene yield was achieved at a Sn loading of 5%, with propane conversion and propylene selectivity reaching 16.6% and 85.2%, respectively. The dehydrogenation performance was significantly enhanced after Cu introduction. At a Cu/Sn molar ratio of 1/1, propane conversion reached 32.9%, with propylene selectivity of 91.6%. The incorporation of Cu not only increased the melting point of the active phase through the formation of CuSn alloys but also optimized the catalyst acidity, facilitating efficient C–H bond activation and suppressing coke formation. Meanwhile, the electronic effects induced by Cu modulated the chemical environment of Sn, promoting the reduction of Sn species, regulating propylene adsorption strength, and inhibiting deep dehydrogenation and cracking reactions. This alloy strategy provides a new approach for designing highly efficient propane dehydrogenation catalysts.