To balance the contradiction between high-viscosity sand carrying during hydraulic fracturing and low-viscosity backflow after fracturing, in this paper, a thickener P(AM/AA/VPBA)-PVA for fracturing fluid containing borate ester dynamic covalent bonds was prepared through a two-step reaction. Firstly, the phenylboric acid functional group was introduced into anionic polyacrylamide to obtain polymer P(AM/AA/VPBA). Then, boric acid ester hexatomic ring was prepared by the reaction of boric acid group with polyvinyl alcohol (PVA). The intermediates and thickeners were characterized by various methods such as Fourier transform infrared spectroscopy, nuclear magnetic resonance 1H spectroscopy, molecular weight, and thermal gravimetric analysis. In addition, studies on recyclability, temperature resistance, salt resistance, viscoelasticity and sand-carrying property of P(AM/AA/VPBA)-PVA solution were carried out. The results show that PVA with mass fraction higher than 0.3% can effectively cross-link 0.5% P(AM/AA/VPBA) solution, and this cross-linking system can be thoroughly depolymerized by 3% glycerol. An increase in pH value from 4 to 11 is beneficial to the formation of cross-linked networks, and the gelation and network regeneration of P(AM/AA/VPBA)-PVA can be achieved through pH regulation. P(AM/AA/VPBA)-PVA solution has a temperature-responsive " thickening-gel breaking" effect, which will be conducive to the performance regulation of P(AM/AA/VPBA)-PVA at different stages of the entire fracturing process.