<p>Extracting Cu by hydrometallurgical methodology is of great significance and advantage for utilizing complex copper sources. As an electro-hydrometallurgical extracting methodology that integrates some unit operations like leaching, purification, and electrodeposition, slurry electrolysis (SE) has attracted considerable attention in extracting Cu from copper resources, because it offers several advantages, such as greenness, low energy consumption, environmental compatibility, etc. By initially introducing the basic principles of SE, this work reviewed the research progress on SE recently used to extract copper from the primary resources (such as chalcopyrite concentrate and complex multi-metallic ores) and secondary resources (such as metallurgical residues and waste printed circuit boards). The regulations of extraction efficiency, morphology of electrodeposits, and energy consumption of SE have been analyzed. Moreover, the anodic mechanisms (including the sequence/passivation/ways of mineral oxidation/dissolution/leaching) and cathodic mechanisms of SE are also discussed from the perspectives of thermodynamics, kinetics, electrochemistry, and species analysis. Finally, the challenges and development of SE have been examined and envisaged.</p>