Objective Coal in-situ conversion (ISC) emerges as an important transformative technology for clean and efficient utilization of coal resources. However, safe and stable coal ISC is currently restricted by two major bottlenecks: an unclear understanding of the mechanisms underlying the geological environment’s dynamic responses and a lack of damage reduction-oriented geological guarantee.

Methods To construct a damage reduction-oriented geological guarantee system for safe and green coal ISC, this study, from the perspective of the geological environment’s dynamic responses throughout coal ISC, elucidates the scientific connotations of both the dynamic responses and the geological guarantee in coal ISC. Based on the analysis of the technical cores and geological dependence of two primary modes of coal ISC (i.e., underground coal gasification and in-situ pyrolysis), this study systematically identifies key geological factors influencing the siting, production, and safety of coal ISC. Furthermore, it reveals the evolutionary characteristics of six aspects related to coal ISC: the morphological evolution of coal ISC zones, stratigraphic movement, fracture development, the activation of geological structures, groundwater flow field reconstruction, and the migration of toxic and hazardous substances. Besides, it analyzes the disaster-causing mechanisms of these aspects.

Results Dynamic geological guarantee for coal ISC focuses on (1) perceiving omnidirectional dynamic information about geological structures during coal ISC, aiming to build transparent geological models; (2) clarifying the evolutionary mechanisms of the damage and sealing performance of surrounding rocks under the coupling of thermal, hydraulic, mechanical, and chemical fields to enable the real-time assessment of their failure risks; (3) identifying the patterns and evolutionary pathways of geological damage risks for the purpose of both geological stability control and the proactive intervention in environmental risks, and (4) evaluating geological system evolution and surface ecological responses and developing ecological restoration technologies. Key scientific and technical challenges persist in coal ISC, including unclear dynamic response mechanisms under multi-physical field coupling, a limited understanding of trans-scale damage to the sealing performance of surrounding rocks, a lack of methods for multi-dimensional perception and intelligent recognition, scarce technical reserves for proactive control, and the absence of whole-process intelligent decision-making platforms. To address these issues, this study proposes a five-in-one implementation pathway that integrates dynamic perception, model-based prediction, proactive control, intelligent decision-making, and knowledge-driven strategy. Regarding dynamic perception, it is necessary to construct dynamic perception systems that incorporate multi-physical field coupling to determine surrounding rock responses to coal ISC. For model-based prediction, methods should be devised to predict the sealing performance evolution and failure risks of surrounding rocks based on the temperature-stress-seepage-chemical multi-physical field coupling theory. In terms of proactive control, it is advisable to research and develop damage reduction-oriented control technologies centered on both monitoring for early warning and proactive intervention. Regarding intelligent decision-making, platforms that integrate multi-source data should be established for full-process intelligent decision-making and collaborative resource utilization. In addition, the knowledge-driven strategy necessitates developing multi-source case base-grounded, knowledge graph-driven technology iteration systems for damage reduction-oriented geological guarantee.

Conclusions The results of this study will provide critical theoretical and technical guidance for the safe and sustainable operation of coal ISC, thereby serving as a valuable guide for serving national major strategic needs and achieving the transformation, upgrade, and high-quality development of China’s coal industry.