Abstract: High stress broken chamber has the characteristics of strong flowing deformation, large deformation, and reasonable reinforcement approach is the assurance of safety and stability of chamber. Taking Changping 4303 substation’s reinforcement as a study object, through analyzing the surrounding rock, stress condition and deformation and failure mechanism, we propose the reinforcement method to transfer surrounding rock stress, including inverted arch closure supporting and composite anchor cable reinforcing and deep hole high pressure grouting. The research indicates that the combination of inverted arch closure support and composite anchor cable reinforcing can reduce fractures. Deep hole grouting can transfer the high stress of surrounding rock to deep rock. Combination reinforcement can prevernt the damage of surrounding rock and reduce the deformation amount of surrounding rock.