Leakage prevention forms a closed full-cycle system: compatible anti-corrosion material matching eliminates corrosion root causes; vibration and erosion optimized structural design avoids structural crack defects; factory dual pressure testing removes manufacturing hidden dangers; standardized installation prevents assembly seepage; scientific operation slows corrosion and fouling; regular inspection captures micro-leakage at early stage before total tube perforation. For marine seawater-cooled copper-nickel bearing oil coolers, continuous execution of all above measures can extend service life to 15–25 years with zero unplanned leakage failures.