The invention relates to the field of corrosion fatigue crack measurement, in particular to a corrosion fatigue crack growth test device, which is suitable for measuring the corrosion fatigue crack growth rate and threshold value of materials by the flexibility method, and solves the problem of the fatigue test when the sample is clamped in the prior art. The loading direction of the machine has special requirements, or the parameters of the flexibility formula need to be modified during the clamping extension timing, and the solution is easy to leak. The device includes a load application system, a crack detection system and a temperature control system. The device of the present invention is easy to operate, install and use, and the conventional vertical fatigue testing machine can be used to load the CT sample in the solution, which effectively avoids the leakage of the solution, does not need to modify the flexibility formula, and is suitable for the calculation of the flexibility method at room temperature or high temperature solution Testing of corrosion fatigue crack growth rate and threshold value of materials. Its temperature control is accurate, and it can measure the corrosion fatigue crack growth rate and threshold value of materials under normal temperature solution and high temperature solution, and it is easy to observe the corrosion state of the sample in real time.