High-temperature-resistant viscosity reducer and preparation method thereof

The invention relates to the technical field of oilfield chemical auxiliaries, and discloses a high-temperature-resistant viscosity reducer and a preparation method thereof. The high-temperature-resistant viscosity reducer is prepared from the following raw materials in parts by weight: 10 to 30 parts of vinyl propionate, 20 to 40 parts of styrene, 10 to 20 parts of cyclohexyl methacrylate, 5 to 12 parts of sodium methacrylate sulfonate, 3 to 8 parts of an emulsifier, 0.5 to 3 parts of an initiator, 10 to 50 parts of water, 15 to 40 parts of beta-cyclodextrin modified organic silicon and 8 to 25 parts of gamma-polyglutamic acid. Wherein the beta-cyclodextrin modified organic silicon is prepared from beta-cyclodextrin and organic silicon, and the weight ratio of the beta-cyclodextrin to the organic silicon is (0.1 to 0.5): 1. The prepared high-temperature-resistant viscosity reducer is excellent in high-temperature resistance, stable in performance, good in viscosity reduction effect, free of heavy metal chrom