Abstract: Due to the inability of conventional seawater based fracturing fluid systems to meet the requirements of high salinity seawater configuration and stable properties in high-temperature reservoirs, experiments are conducted on the selection of fracturing fluid additives and performance evaluation using East China Sea seawater as a sample. Four additives, FLICK-2 salt resistant thickener, high-temperature cross-linking agent, multifunctional composite synergist and gel breaker are selected to form a fracturing fluid system which withstands temperature up to 175 ℃ and can be quickly mixed with seawater up to 60000 mg/L. The fracturing fluid system has good temperature resistance and shear resistance, and the viscosity of the system can still be maintained higher than 50 mPa·s at 175 ℃ after 2 hours at a shear rate of 170 s⁻¹.