High-temperature-resistant viscosity reducer for drilling fluid and preparation method thereof

The invention discloses a high-temperature-resistant viscosity reducer for drilling fluid and a preparation method thereof, and relates to the technical field of drilling fluid viscosity reducers, specifically, drilling fluid ingredients comprise a base material, a viscosity reduction component A, a viscosity reduction component B and an auxiliary component, the base material specifically comprises fresh water, crude oil, bentonite, a thickening agent, a filtrate reducer, a cosolvent, a solubilizer and a gelling agent, and the viscosity reduction component A is a viscosity reduction component B; the viscosity reduction component A specifically comprises aluminum potassium sulfate dodecahydrate, sodium hexametaphosphate, sodium bicarbonate and sodium citrate, and the viscosity reduction component B specifically comprises alkali, short-chain alcohol, xanthan gum and a freezing point inhibitor. The auxiliary components are specifically a mixture of alkyne diol polyether and trisiloxane polyether, alkyne diol pol