Abstract: In this paper, a detailed investigation and research on the failure of drilling tools in medium and deep geothermal exploration and production combined well is carried out. Qualitative analysis method is adopted to comprehensively analyze the drilling formation, parameters, materials and drilling tools structure and other factors,and statistical research is carried out on the actual drilling data to obtain the reasons for the failure of drilling tools in geothermal well, and reasonable treatment measures and preventive measures are proposed. At the same time,the experience and lessons are summarized, the existing drilling process is studied and improved, and the targeted improvement plan and new technology are proposed to provide favorable drilling parameters for the efficient drilling of subsequent geothermal production Wells, provide reference for the drilling of the same type of medium and deep geothermal Wells, avoid the recurrence of similar drill tool failure accidents, and improve drilling quality.