This research work focused on the process development for dissimilar clinch joints in aluminum alloy 5052-H32 (AA5052-H32) and thermoplastic carbon fiber reinforced plastic (Thermoplastic-CFRP) sheets, including process development of clinching, shear tensile testing, and shear fatigue testing. First, AA5052-H32 and thermoplastic CFRP sheets with a thickness of 1.6 mm were used. The punch and die were improved by examining tensile test results and metallographic micrographs. The influence of punching force on the process was discussed. Finally, some better processing parameter sets were obtained. After developing the clinching process, we further conducted a series fatigue tests for Al/CFRP dissimilar clinching joints. The fatigue failure modes of joints were analyzed and the failure mechanisms of joints were discussed.