2-hydroxy-3-n-octadecyloxy propyl guarhum （HOPG） was synthesized with guar gum（GG） as material，using n-octadecyloxy propyl glycidyl ether（OPGE）as the hydrophobic reagent，sodium hydroxide as catalyst and 95% ethanol as solvent through ring opening addition reaction. The crosslinking performance，temperature resistance and shearing performance，breaking performance of the HOPG fracturing fluid were evaluated by simulating the scene formula. The experimental results showed that the HOPG had better solubility and crosslinking performance. When breaking the gelled fracturing fluid，composed of 0.3% HOPG + 0.3% JL-13+0.2% APS，at 90℃ for 1 h，the insoluble content of the broken fluid was only 182 mg/L，and the viscosity of the broken fluid was only 1.02 mPa·s，which was obviously lower than that of the broken fluid prepared with the GG. Moreover，the temperature resistance and shear resistance of the HOPG fracturing fluid was better，the apparent viscosity of the HOPG fracturing fluid was 165 mPa·s when sheared for 70 min at the temperature of 80℃and at the shear rate of 170 s^-1.