High temperature-resistant polymer (HTP) was synthesized by in-situ cross-linking of interpenetrating reaction using H-2 monomer containing amide bond and H-1 molecule containing hydroxyl as raw materials. IR spectra result showed that there were characteristic functional groups of H-1 and H-2 cross bond at the same time, that was to say that H-1 cross-linking reaction and H-2 polymerization could simultaneously take place. The interpenetrating cross-linking structure, extension properties at room temperature and long-term heat resistance properties of the material were tested. The experiment results showed that in the whole range of observations, HTP material cross-links and interpenetrates uniformly. The SEM pictures confirmed the interpenetration structure of HTP material. After cross-linking and interpenetration, the scale of HTP structure became smaller than before. This material had tensile resistance, dispersion stability in water, volume expansion, and could reach the maximum swelling ratio of 1.69 within 1.5 hrs at room temperature. At 90℃, 120℃ and 140℃, after soaking 130 days in formation water, HTP volume reduction rate was 1.57%, 3.24% and 6.82%, respectively.