Proton exchange membrane fuel cells (PEMFCs) are crucial for the advancement of hydrogen energy applications, but efficiency is hindered by sluggish cathode kinetics. Alloying Pt with transition metals can enhance catalyst activity, but durability is a challenge. Recent studies focus on enhancing the stability of Pt-M alloys through orbital modulation, particularly in chemically ordered L10-PtM intermetallic alloys. A new strategy involving quasi-covalent bond networks within Pt crystallines has been developed to improve the catalytic stability of intermetallic L10-PtMM' nanocrystals for PEMFCs. By increasing bonding-antibonding energy level splitting, a conversion from metallic to covalent interaction is achieved, enhancing atomic bond strength. Operando characterizations reveal that the L10-PtCoCr catalyst effectively reduces catalyst attenuation by suppressing metal corrosion and surface oxidation. The L10-PtCoCr/C catalyst shows excellent performance in PEMFC tests under LDV conditions, demonstrating high activity and durability with low Pt loading. The study provides insights into the bonding characteristics of L10-PtCoM' catalysts and their impact on structural stability, offering a promising solution for improving the efficiency and longevity of PEMFCs.