Abstract: Through the research methods of site research, laboratory experiment, numerical calculation and industrial tests, we summary instability process of seepage argillaceous roadway and the key factors caused its changes, analyze the mineral component of natural mudstone and micro process of mudding, simulate mudding of surrounding rock on damage results of roadway, and find that all aspects of performance of mudstone mainly depends on clay minerals given priority to montmorillonite, and with hydration process of clay minerals especially montmorillonite, the micro structure of mudstone gradually damaged, and led to reduction of mudstone cohesion, thus appeared mud rheological phenomenon to lead to instability and failure of argillaceous roadway on the macro. Finally, we propose dewatering and pressure relief, strengthening surrounding rock and constructing high strength supporting system three safety control measures, which effectively solves the muddy roadways instability problems.