Geodiversity encompasses the variability within Earth"s abiotic environment, including geological, geomorphological, pedological and hydrological attributes. It holds multidimensional value, significantly shaping biodiversity and supporting ecosystem and geosystem services. In the context of global environmental change, Essential Geodiversity Variables (EGVs) offer comprehensive insights into Earth"s surface processes, aiding climate adaptation, systematic conservation planning, human well-being and sustainable development. Over the past 30 years, geodiversity research has expanded, resulting in a wider range of topics and deepening connotations. However, a systematic synthesis is lacking, and key questions, particularly regarding underlying mechanisms, remain unresolved. To this end, this paper reviews the evolution of geodiversity theory and research progress by examining its conceptual development, methodologies, the relationship between geodiversity and biodiversity (GBD), and the linkages between geodiversity and ecosystem services with bibliometrics-assisted analyses. The results show that the connotation of geodiversity has undergone an evolutionary process of "beginning – enrichment - establishment of mainstream - generalization", reflecting increasing research diversity but also introducing ambiguity and subjectivity. Methodological approaches to assessing geodiversity commonly employ spatial grids and classical biodiversity indices. The GBD relationship is widely recognized, and preliminary quantitative evidence indicates that its intensity varies across scales and ecosystem types. The relationship of GBD has been widely recognized and preliminary quantitative statistical evidence has been obtained, but it varies significantly across scales and ecosystem types. Research on geodiversity"s role in supporting ecosystem services remain nascent, predominantly focusing on conceptual frameworks and suffering from a significant scarcity of quantitative studies. While some research explores the connection between geodiversity and cultural services, less attention has been given to regulatory and supporting services, with mechanisms still underexplored. To address these issues, this paper proposes three future directions: clarifying and refining geodiversity concepts and developing locally adapted assessment tools, integrating GBD research with a focus on mechanisms and scale effects, and advancing multiscale research on the linkages between geodiversity and ecosystem services.