To address the technical challenges of poor gelation stability and short service life of conventional polymer gels in the high-temperature and high-salinity (HTHS) environments of deep reservoirs, a reinforced polymer gel system was fabricated by compounding the alkaline complexing agent LH-2 and stabilizer WD-1, leveraging the inherent property that polymer gels exhibit superior stability in alkaline media while gelation is inhibited under acidic conditions (pH<5). The gelation regularity and application performance of the developed system were systematically investigated through gelation property evaluation, long-term stability testing, Thermal Gravimetric Analyzer (TGA), and core plugging experiments. Experimental results demonstrate that under the conditions of 45550 mg/L salinity (2000 mg/L divalent ion concentration) and 140 ℃, when the mass fractions of both polymer and cross-linking agent are increased to 0.6%, the gel exhibits a dehydration rate of merely 2.8% after 180 days of aging, with the gel strength maintained at grade D~E. Within the temperature range of 90~140 ℃, the system achieves rapid gelation with a gelation time of 17~24 h. For cores with a permeability of 500×10?³μm², the plugging rate reaches as high as 99.9% and the maximum injection pressure is only 0.19MPa, indicating excellent inject ability and plugging efficiency. This high-temperature resistant and long-term stable gel system provides critical data support and a novel technical approach for the profile control technology in deep HTHS reservoirs.