Abstract: The development of novel radiopharmaceuticals is crucial for the advancement of nuclear medicine molecular imaging. In recent years, the radionuclide ⁶⁴Cu has become a core radionuclide in the development of theranostic radiopharmaceuticals due to its unique decay characteristics and versatile coordination capabilities. Significant advancements have been made in the development of ⁶⁴Cu-labeled drugs, including monoclonal antibodies, peptides, small molecules, and immunoimaging agents, all of which have demonstrated excellent sensitivity and specificity in both preclinical and clinical trials by targeting tumor-specific receptors or characteristic components of the microenvironment. Currently, ⁶⁴Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-D-Phe1-Tyr3-Thr8-octreotide (for the diagnosis of neuroendocrine neoplasms) has been approved by the U. S. Food and Drug Administration, while ⁶⁴Cu-labeled prostate specific membrane antigen (for prostate cancer diagnosis) has shown its clinical value in European. Both achievements validate the potential of ⁶⁴Cu-labeled probes in theranostics for tumors. The authors review the research progress of ⁶⁴Cu-labeled radiopharmaceuticals, covering various types including small molecules, peptides, and monoclonal antibodies, aiming to provide a reference for the design and development of a new generation of diagnostic radiopharmaceuticals.