The runoff coefficient is a critical parameter that quantifies the proportion of rainfall converted into surface runoff and is widely used in water resources management and urban planning. This paper provides a comprehensive review of the concept, historical evolution, determination methods, influencing factors, and research methodologies related to the runoff coefficient. It examines how the runoff coefficient varies under different influencing factors and evaluates the advantages and disadvantages of various research approaches. The study emphasizes the importance of interdisciplinary collaboration in advancing technological innovation, integrating data sources, and balancing cost-effectiveness. In the context of rapid climate change and urbanization, it outlines current challenges and future research directions, highlighting how emerging technologies and methods, such as computer technology, remote sensing, and machine learning, can offer new perspectives for runoff coefficient research and provide scientific support for decision-making in water resources management and urban planning.