The mid-infrared 3?5 μm laser band is located in the atmospheric transmission window and holds highly significant applications in various fields, including environmental monitoring and laser medicine. Combined with nonlinear effects of crystals, generating a mid-infrared laser based on both optical parametric oscillation and optical parametric amplification possesses advantages including high power, large energy, and wide tuning range, which can also facilitate the miniaturization and integration of laser systems by optimizing their pump sources. Among numerous nonlinear crystals, ZnGeP₂ (ZGP) is the preferred crystal for mid-infrared lasers owing to its large nonlinear coefficient, high damage threshold, and other advantages. This study focuses on mid-infrared ZGP lasers based on optical parametric oscillation and optical parametric amplification, by summarizing the latest research advancements in this field, analyzes and summarizes the existing issues with the current technology, and provides an outlook on directions for future development.