The invention provides a method for preparing guargum fracturing fluid, the guargum fracturing fluid prepared by the method and an application of the guargum fracturing fluid. The method comprises thesteps: (a) adding a solubilizer, a screening agent, guargum, a microbicide, a clay stabilizer and a discharge aiding agent into formation water or superficial water, and carrying out mixing, so as toobtain a base solution; (b) adding a cross-linker, a high-temperature stabilizer and a pH regulator into water, and carrying out mixing, so as to obtain crosslinked fluid; and (c) adding the crosslinked fluid into the base solution according to a volume ratio of 100: (1 to 1.5), and carrying out mixing, thereby obtaining the guargum fracturing fluid, wherein the solubilizer comprises one or moreof citric acid, acetic acid and lactic acid, the screening agent comprises one or more of hydroxyl ethylene phosphoric acid, amino trimethylene phosphonic acid and ethylenediamine tetramethylene phosphoric acid, and the high-temperature stabilizer is an organic zirconium compound. According to the method, the rapid-dispersed tackifying of the guargum in the formation water or superficial water ispromoted, the temperature resistance of the fracturing fluid is improved, the fracturing fluid can be applied to reservoirs of 30 DEG C to 140 DEG C, and thus, the effective utilization of highly-mineralized formation water or superficial water is achieved.