In order to solve the problem of poor application effect of polyacrylamide microspheres (P (AM-AMPS)) due to insufficient strength or elasticity, vinyl silicon nanoparticles composite polyacrylamide microspheres (VSNPs-P (AM-AMPS)) were prepared by reverse micro emulsion polymerization with vinyl silicon nanoparticles (VSNPs), acrylamide (AM), 2-acrylamide-2-methylpropane sulfonic acid (AMPS) and other copolymer components. The results showed that the composite microspheres had a spherical morphology, uniform particles, and an average particle size of 63.3 nm. The swelling ratio was 3.3 times at 20 ℃ and 90000 mg/L mineralization for 72 hours, and 4.2 times at 80 ℃ and deionized water for 72 hours, demonstrating good temperature and salt resistance. Compared with P (AM-AMPS) microspheres, the compressive strength of the composite microspheres is nearly doubled, the elastic modulus is increased by 4.1 times, and the sealing rate of the sand filled tube test is increased by 7.8%, reaching 95.6%. The introduction of VSNPs effectively enhances the mechanical strength and elasticity of composite microspheres, making them possess both swelling deformation and strength toughness, further improving the sealing effect.