To study the failure modes and mechanical properties of self-piercing riveted-bonded (SPR-bonded) composite joints in acidic environments, the 0.02 mol/L NaHSO₃ solution was used as the corrosion medium to conduct dry-wet alternate immersion corrosion tests on similar and dissimilar SPR joints and SPR-bonded composite joints. Subsequently, the static mechanical properties of the joints under different corrosion cycles were explored through static tensile tests, and the corrosion behavior at the gaps during the riveting forming process of joints was studied by means of scanning electron microscope. The results showed that the corrosion effect had an impact on the failure displacement of the SPR joint, and the static strength and stiffness of the SPR-bonded composite joint were both superior to those of the SPR joint. The bonded structure was more sensitive to the corrosion effect, which gradually reduced the failure load of the SPR-bonded composite joint, resulting in the failure load of the SPR-bonded composite joint being borne by the riveted structure in the middle and later stages of corrosion. The dissimilar joints exhibited relatively poorer stability compared to similar joints. The incorporation of adhesive effectively inhibited the transformation of failure modes of dissimilar joints in corrosive environments. The adhesive had a certain inhibitory effect on the corrosion in the overlap area between the upper and lower plates of the joint. The scratches on the riveted hole wall of the upper plate would accelerate the corrosion at the contact surface between the outer side of the rivet tube leg and the upper plate. The selection of SPR-bonded composite joints helps to enhance the static strength and corrosion resistance of riveted structures, thereby prolonging their service life. The research results provide theoretical support for the application of riveting technology in acidic corrosive environments.