Abstract: The fault mining of large mining height fully mechanized mining face is a key challenge in coal mining. The existence of faults makes the mining process face complex stress changes and roof stability issues. This paper combines the latest research results to deeply analyze the key technologies of cross fault mining in large mining height fully mechanized mining face, including fault reinforcement technology, stress evolution law, and mining process optimization. The research shows that through techniques such as grouting reinforcement and undercover methods, stress concentration near faults can be effectively controlled, ensuring roof stability and improving mining efficiency. The research results provide scientific basis and technical support for cross fault mining in large mining height fully mechanized mining face.