Preparation method and application of degradable fracturing fluid thickening agent

The invention relates to a degradable fracturing fluid thickening agent as well as a preparation method and application thereof, and belongs to the technical field of fracturing fluid thickening agents. Comprising the following components in parts by weight: 22-33 parts of a ternary polymer, 8-12 parts of octadecyl trimethyl ammonium bromide, 5-10 parts of tripolyglycerol diisostearate and 5-8 parts of sodium tetradecyl carboxylate, wherein the ternary polymer is prepared from the following raw materials in parts by weight: 3 to 5 parts of acrylamide, 5 to 8 parts of methacrylic acid, 12 to 15 parts of N, N-dimethylacrylamide, 1 to 2 parts of potassium persulfate, 1 to 2 parts of sodium hydrogen sulfite and 0 to 1 part of sodium hydroxide. The thickening agent disclosed by the invention is low in impurity content, low in viscosity and good in solubility in fracturing fluid, and almost no residue exists in gel breaking fluid. And the used raw materials are easy to degrade and do not damage the earth surface. T