In this paper, the interaction of double oblique cracks is researched experimentally and numerally. Fatigue crack growth tests of both the single crack and double crack specimens are conducted to investigate the effect of crack interactions on fatigue crack growth behaviours. Results indicate that the oblique crack has a shielding effect on the crack growth length of the dominant crack. In addition, numerical simulations show that the stress intensity factors at the dominant crack tips in the double crack specimens are smaller than those at the crack tips in the single crack specimens, which explains why the growth length of the dominant crack decreases in the present of the oblique crack.