HKUST-1 is known as an important copper-based metal–organic frameworks because of its high specific surface area, permanent microporosity, accessible open Cu sites, and broad applicability in various fields. However, conventional solvothermal preparation of HKUST-1 commonly relies on large quantities of organic solvents, extensive washing and activation steps, and poorly recyclable mother liquors that limit its compatibility with green chemistry principles and large-scale production. This review critically explains recent progress in sustainable and function-oriented synthetic strategies for HKUST-1, with emphasis on solvent decrease or elimination, precursor efficiency, process circularity, defect engineering, metal doping, monolithic shaping, and composite integration. These studies demonstrate that greener synthesis can be coupled with competitive or enhanced properties, including high BET surface areas, large pore volumes, controlled defect densities, and improved accessibility of active sites. In addition, future advances will require synthesis protocols that are not only environmentally benign and resource-efficient, but also reproducible, scalable, and compatible with practical device or process architectures.