Abstract: Silver-chalcogenide (Ag₂X, X=S, Se, Te) colloidal quantum dots (CQDs) are a class of nanomaterials with outstanding optoelectronic properties. Benefiting from their eco-friendly nature, size tunability, and bandgap controllability, they have been widely applied in various fields such as optoelectronics and bioimaging. Ag₂X CQDs particularly exhibit high detectivity, fast response, and broadband detection capability in photodetectors. Although silver-chalcogenide CQDs have many advantages, its research is still in the development stage, facing challenges including poor synthesis stability, limited exploration of ligand exchange, and relatively narrow options for functional layer materials in practical applications. Therefore, this review summarizes the recent progress in the synthesis, ligand exchange strategies, and photodetector applications of silver-chalcogenide CQDs. Firstly, the synthesis methods of the three types of CQDs are systematically reviewed, with discussion about the influence of reaction conditions (reaction time, temperature, ligand species) on their size, morphology, and optical properties. Secondly, ligand exchange strategies are analyzed in detail with respect to their roles in tuning surface chemistry, stability, and charge transport properties, and the optimization of optoelectronic properties through different ligand systems. Finally, the applications of silver-chalcogenide CQDs in photodetectors are summarized, highlighting their advantages and challenges in terms of detectivity, response speed, and device architecture design, thereby providing references for the further development of non-toxic quantum dots.