Fiber reinforced plastics shields are used in the development of offshore oil and gas fields in the South China Sea to protect critical facilities in underwater production systems. Fiberglass (FRP) is the most commonly used composite material， widely used in Marine and ocean engineering fields. By establishing the seawater corrosion resistance life model and defining the bending strength retention rate， the general equation of seawater corrosion resistance life and the seawater corrosion resistance life formula under deepsea low temperature conditions are obtained. Based on the flexural strength test results of longterm immersion in seawater at room temperature and high temperature， from the point of view of bending strength， corrosion resistance is short. it is predicted that the corrosion resistance life of glass fiber reinforced vinyl ester composites in the seawater temperature range of 0-4℃ is about 12.28-16.55 years for applications subject to low bending loads.