The organic boron crosslinking agent JSA-1 was synthesized using boric acid, n-butanol, ethylene glycol, and diethylenetriamine as raw materials using a one-pot method. The crosslinking performance of JSA-1 was systematically evaluated by examining factors such as the mass fraction of guar gum (the percentage of guar gum to the total mass of guar gum base solution), the dosage of JSA-1 (based on the quality of guar gum base solution), and pH. The results show that the higher the mass fraction of guar gum (0.09%~0.4%), the better the crosslinking state, shorter the crosslinking time, higher the apparent viscosity, and stronger the temperature resistance of guar gum fracturing fluid; The larger the dosage of JSA-1 (0.04%~0.4%), the better the crosslinking state, shorter the crosslinking time, and stronger the temperature resistance of guar gum fracturing fluid; The higher the pH (pH=4~14), the longer the crosslinking time and stronger the temperature resistance of guar gum fracturing fluid. JSA-1 has a wide range of applications for pH and guar gum mass fraction. In terms of low-temperature formula, it can effectively crosslink low mass fraction guar gum. When the guar gum base solution with a mass fraction of 0.13% is crosslinked with JSA-1, the apparent viscosity can reach 50 mPa·s at room temperature shear. In terms of high-temperature formula, the fracturing fluid prepared by cross-linking a 0.4% guar gum base solution with JSA-1 has good temperature and shear resistance, and its apparent viscosity can be stably maintained at around 300 mPa·s under 120 ℃ shear conditions.