Abstract: The development and utilization of innovative green solvents is currently a hot topic of research. Substituting conventional solvents with environment friendly alternatives in the pretreatment of ecological geological samples can effectively mitigate potential risks to both researchers and the environment. Deep eutectic solvents (DESs) have garnered increasing attention due to their biodegradability, minimal environmental impact, cost-effectiveness and facile synthesis, rendering them suitable for extraction and separation in eco-geological sample analysis. This paper comprehensively overviews the deep eutectic solvents (DESs) from the perspectives of its conceptual framework, preparation methodologies, and essential physicochemical properties. Additionally, it summarizes latest research advances on applying DES technology to water quality assessment, soil analysis, and biological sample characterization with the discussion of its prospects. As a new type of green solvent, DESs offers a promising alternative to replace conventional toxic solvents; however, it is crucial to address challenges related to high viscosity along with further investigation in extraction mechanisms and integration with various detection techniques.