Abstract: Carbon fiber reinforced polymer (CFRP)-Al single-lap adhesive joints were made at room temperature. Firstly, a universal testing machine as well as an electro-hydraulic servo fatigue testing machine were used for quasi-static tensile tests and tensile-tension fatigue tests, respectively. Based upon the fatigue test results and two-parameter Weibull distribution methods, multiple function models were applied to fit the stress-life (S-N) curves of joints. Meanwhile, 3D digital image correlation (3D-DIC) and SEM were used respectively to obtain the strain field distribution and failure morphology of joints, revealing the failure mechanism of joints under cyclic load. According to the test results, the power function has the highest fitting degree for the S-N curves of the joints, with the correlation coefficient R² of 0.987. Besides, with the load level decreasing, the fatigue life and the coefficient of variation of the joints gradually increase. When the load levels are 25% and 35% of the failure load, the failure modes of joints are mainly cohesive failure and interface failure. And the cohesive failure area increases correspondingly with the increase of the load level. Even when the load level is up to 75% of the failure load, only cohesive failure occurs. Moreover, when the load level is 25% of the failure load, ductile fracture occurs due to the increase of the internal temperature of the joints. And when the load level rises to 75% of the failure load, the joints gradually change to brittle fracture as a result of large tensile stress.