Due to the long-term chloride corrosion, the prestressed concrete box girder in the marine condition is often destroyed, so it cannot meet the requirement of the durability of 100 years. This paper puts forward a series of technical measures, namely, improving the durability of concrete, increasing the concrete cover thickness, painting silane in the surface, using the stainless steel, and adding the corrosion inhibitor. Moreover, based on the reliability theory, the corrosion probability of the main girder in the first rank of the prestressed concrete box girder by different measures is analyzed and compared. And then, some probable technical methods for the prestressed concrete box girder are obtained to meet the requirement of long service life, which can provide a valuable reference for the practical engineering.