The activity of PtSn/Al₂O₃ catalyst has a significant impact on the activity and stability of propane dehydrogenation catalysts. To address the issues of easy migration and agglomeration of the active component Pt, which make it difficult to maintain high dispersion, the active phase of the catalyst was regulated by changing the precursor of the active component Pt, and its effect on the propane dehydrogenation performance was investigated. Characterization and analysis of the active phase and carbon deposition resistance of the catalyst were carried out using TEM, H₂?TPR, TG, and Raman techniques. The results showed that under conditions with similar propane conversion rates, the selectivity of propylene increased from 86.96% to 93.92%, while the production of by?product methane significantly decreased. The catalyst prepared using octaethylporphyrin platinum as the precursor had a smaller active phase size and better dispersion. Using octaethylporphyrin platinum as the precursor can enhance the interaction between Pt and the support, significantly improve the stability of the active phase, effectively improve the catalyst's resistance to coking, and significantly reduce the amount of carbon deposition.