Abstract: The fatigue crack growth rate of F690 super-high strength steel in simulated seawater was measured by direct-current voltage drop method, and the effects of stress ratio (0.1,0.2,0.3) and loading frequency (0.15,0.30,0.60 Hz) on the fatigue crack growth behavior were studied. The corrosion fatigue process was simulated by the extended finite element method based on Paris law of energy release rate, and compared with test results. The results show that the corrosion fatigue crack growth rate of F690 steel in simulated seawater decreased with increasing stress ratio or frequency. The corrosion fatigue fracture mode was transgranular fracture, and with increasing frequency, the width of secondary cracks decreased. The simulated corrosion fatigue crack growth length of F690 steel was consistent with the test results, and the relative error was less than 0.6%, indicating that the corrosion fatigue crack growth behavior of F690 steel could be effectively simulated and predicted by the extended finite element method.