<p>In the exploitation of high-salinity oil and gas reservoirs, traditional fracturing fluid thickening agents often encounter challenges such as poor solubility, reduced thickening efficiency, and unstable rheological properties due to the high concentration of salt ions. To address these issues, this study presents the design, synthesis, and comprehensive performance evaluation of a novel salt-tolerant supramolecular thickening agent (STSTA) based on hydrophobic association and electrostatic interactions. The STSTA was synthesized via aqueous solution polymerization using acrylamide (AM), acrylic acid (AA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), a non-ionic polymerizable surfactant (NPS), and a double-tail hydrophobic monomer (DHM) as the main monomers. Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM) were used to characterize the chemical structure and morphology of the STSTA. Performance evaluations included solubility, thickening ability, rheological behavior, salt tolerance, sand-carrying capacity, thermal stability, and compatibility with other fracturing fluid additives. The results showed that the STSTA exhibited excellent solubility in salt brines up to 200,000 mg/L, maintained high viscosity (≥80 mPa·s at 0.5 wt% concentration under 170 s^-1 shear rate in 150,000 mg/L NaCl), and demonstrated superior shear-thinning, viscoelastic, and shear-recovery properties compared to traditional guar gum-based thickeners. The unique supramolecular structure formed by hydrophobic association and ionic interactions enabled the STSTA to resist salt-induced viscosity degradation, making it a promising candidate for hydraulic fracturing in high-salinity environments.</p>