As the hole wall collapse and leakage in the process of geothermal development， and the conventional cement-based materials deteriorates under the condition of high temperature， which can not meet the requirements of the wall protection and leakage control. A series of experiments and theoretical analysis were studied to solve such realistic problems. A variety of materials and reagents are selected for orthogonal experiment to obtain the optimal formula. Through experiments， high temperature resistance is compared between ordinary Portland cement and G-grade oil well cement in terms of four performance indexes of initial fluidity， pumping period， setting time and compressive strength， and the relatively stable cement suitable for research at high temperature is selected； In order to solve the problem of cement performance degradation at high temperature， several silica containing materials and reagents were selected， and the formula was optimized by orthogonal test. The optimized formula was as follows： 25% GS+0.6% SiO₂ +0.3% JSS+1.5% SN+0.03% SC+0.3% nano material. The performance evaluation results show that the fluidity and other properties of the formula meet certain construction requirements， and have good compressive strength at high temperature.