In proton exchange membrane water electrolysis (PEMWE), catalysts for acidic oxygen evolution reaction (OER) that demonstrate high current density and stability are essential. Herein, we synthesized La-doped RuO2 (La-RuO2@TM) nanorod composite catalysts in situ on titanium mesh (TM) using a one-step low-temperature pyrolysis method. La-RuO2@TM displays excellent catalytic performance (1.533 V at 100 mA cm-2) and remarkable stability, showing no significant degradation in performance over 450 hours of operation. Density functional theory (DFT) calculations indicate that the formation of the La-O-Ru local structure modulates the adsorption strength of reaction intermediates, alleviates metal (Ru) leaching, and reduces oxygen loss, significantly enhancing the material's durability in acidic OER. The PEM electrolyzer utilizing La-RuO2@TM operates at 1.815 V with a current density of 1.0 A cm-2, maintaining stable performance for 120 h at 60°C. This study offers valuable insights for designing efficient and durable acidic OER catalysts.