The invention discloses a hydroxypropyl guar gum fracturing fluid containing potassium monopersulfate and a preparation method thereof, belongs to the petrochemical field, particularly relates to the hydroxypropyl guar gum fracturing fluid containing potassium monopersulfate, and aims to provide the hydroxypropyl guar gum fracturing fluid containing potassium monopersulfate and having quick gel breaking and good residue degradation effect. The hydroxypropyl guar gum fracturing fluid is composed of a crude gum fluid and a crosslinking agent, and the addition amount of potassium monopersulfate in the hydroxypropyl guar gum fracturing fluid is 5-20 ppm. After the use of potassium monopersulfate, the hydroxypropyl guar gum fracturing fluid not only has a bactericidal effect but also improves the gel breaking speed; in addition, potassium monopersulfate and ammonium persulfate in the fracturing fluid form a composite gel breaking system, the gel breaking speed and the residue degradation effect are further improved, and potassium monopersulfate is low in cost and has no any pollution on stratum water quality.