Propane dehydrogenation (PDH) is an efficient technology for the direct production of propylene. Nevertheless, current PDH catalysts mainly rely on precious Pt or toxic Cr and especially undergo severe coke deposition. Herein, we report a Ru catalyst decorated by boron species (Ru-3B/AlO), which exhibits high catalytic performance for PDH. HAADF-STEM, EELS, and CO-FTIR characterization are used to identify the surface structure of the Ru active component, which shows that the high-energy unsaturated coordination sites, including corners, edges and step atoms for Ru-3B/AlO are appropriately modified by BO species. The encapsulation of high-energy active sites prone to C-C cracking and deep dehydrogenation leads to higher propylene selectivity (> 95%) and strong carbon resistance ( 0.0007 min) over Ru-3B/AlO. The XPS and H-TPR results show that the migration of B species is driven by the reduction of BO to BO and that the coating degree of Ru particles is controlled by the chemical valance of Ru species.