<p>In this study, acrylamide (AM), acrylic acid (AA), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), and 4-acrylamido-morpholine (ACMO) were used as the raw materials, and the hydrophobic monomer, hexadecyl dimethyl allyl ammonium chloride (DMAAC-C₁₆), and the cross-linking agent poly(ethylene glycol) 200 diacrylate (PEG200DA). A slow-expanding temperature- and salt-resistant polymer nanomicrospheres (PHM) were prepared by reverse-phase microemulsion polymerization. The PHM structure was characterized using infrared spectroscopy, nuclear Magnetic resonance spectroscopy, and scanning electron microscopy, and their properties were analyzed nano-laser particle sizing, and rheometry and employing the filtration factor. The results showed that the average particle size of PHM microspheres was 68.69&#xa0;nm, and the swelling multiplicity of PHM microspheres was 4.34 times after dissolving in water for four days at 80 ℃. The swelling multiplicity of PHM microspheres after dissolving in mineralized water with a mineralization level of 8 × 10⁴&#xa0;mg/L for four days at 25 ℃ was 2.34 times, with a blocking rate of more than 85%. The viscoelasticity test showed that the PHM microspheres have good elasticity and good injection performance. Compared with the conventional microspheres (PCM), the introduction of DMAAC-C₁₆ and PEG200DA improves the intermolecular bonding of PHM microspheres as well as the elasticity of the molecular chain, which makes PHM microspheres show excellent performance in temperature and salt resistance, slow expansion and viscoelasticity.</p> Graphical Abstract <p>PHM microsphere initial particle size of 68.69nm, in 80℃ (deionized water) in the expansion of 4 days, the expansion times for 4.34 times; 25℃ (mineralized water) in the expansion of 4 days, the expansion times for 2.34 times, the blocking rate is greater than 85%.</p> <p></p>