Abstract: Coal mine underground reservoir technology can increase mine water utilization rate to over 80% through systematic collection, storage and resource utilization of mine water, making it an important technical approach for mine water protection and efficient utilization in western mining areas. Based on patent data from the PatSnap platform, this paper adopts patent bibliometric analysis to systematically study the technology from five perspectives: global patent application trends, geographical distribution, technical composition, innovators, and technological development paths. It summarizes the current status and characteristics of patent applications worldwide, and clarifies the technological evolution and research focuses. The results show that China holds an absolute technological advantage in this field, with numerous leading enterprises and innovators, and its patent output far exceeds that of other countries or regions. Technologically, the development of coal mine underground reservoir can be divided into four stages: initial exploration, technical system establishment, intelligent and precise upgrading, and international expansion. Key patent layout and development directions include reservoir site selection, water source prediction, artificial dam construction, coal pillar dam anti-seepage and reinforcement, monitoring and early warning, and safety assessment.