High temperature deep wells have problems such as reverse thickening time of cement slurry， decline in high-temperature strength，high brittleness and low toughness of cement sheath，which can easily cause failure of cement sheath sealing. The hydrophilic adhesive flexible gel material was prepared by using epoxy resin，anhydride curing agent，dimethylol butyric acid and other raw materials. Then it was mixed with cement，formaldehyde acetone polycondensate dispersant，AMPS multi copolymer fluid loss additive，acrylic acid polyalcohol propylene ether polymer retarder，organic silicon defoamer，and high temperature resistant stabilizer（300 mesh silicon powder）to prepare high temperature resistant flexible cement slurry. The content of each component in flexible cement slurry was optimized. Then the rheological property，water loss，thickening performance and high-temperature strength stability of cement slurry，and the mechanical property and elastic toughness of cement stone were evaluated. The results showed that the flexible gel material had good elasticity，toughness and hydrophilicity，and could improve the mechanical property of cement stone. The optimum formula of flexible cement slurry was obtained as follows：100% cement， 40% water，4.5% fluid loss additive，2% retarder，0.6% dispersant，1% defoamer，10% flexible gel material，36% stabilizer. At 160—200 ℃ ，the flexible cement slurry had good rheological property，thickening property and high-temperature strength stability，with flowability index of 0.87—0.97，viscosity coefficient of 0.46—0.23 Pa·sn，water loss less than 50 mL，and thickening time greater than 300 min. Cement stone had excellent mechanical property，with flexural strength greater than 5.5 MPa and impact strength of 2.79 MPa after 28 days of curing at 200 ℃. Furthermore，cement stone had good flexibility and elastic deformation ability，with elastic modulus of 4.1 GPa at 180 ℃ and confining pressure of 21 MPa，which met the requirements of high-temperature cementing operations in oil and gas well.