TA17 titanium alloy was an important structural material in aerospace engineering， and its fatigue crack propagation behavior directly impacted the safety and integrity of the entire structure.Based on the fatigue crack growth tests of compact tension specimens of Cr2Ni2MoV steel with oblique initial crack， the XFEM module in ABAQUS software was verified in analyzing fatigue crack propagation performance under plane stress conditions， and then the XFEM module was applied to analyze the fatigue crack propagation properties of TA17 titanium alloy and connection.The research results indicate that reducing the maximum load， decreasing the loading ratio， and utilizing obround holes can effectively enhance the fatigue life of TA17 titanium alloy connection. The S-N curve used to predict the fatigue life of the connection is obtained by adopted of XFEM module. When the load of TA17 titanium alloy is increased by 33.3%， the predicted fatigue life is reduced to 1/4， which provides reference for the engineering fatigue design of the TA17 titanium alloy structure.