Production process for high-temperature salt-resistant viscosity reducing filtrate reducer for drilling fluid

The invention provides a production process for high-temperature salt-resistant viscosity reducing filtrate reducer for drilling fluid. The process comprises the following steps of: adding 260g of purified water into a reaction kettle, heating to 95 DEG C, adding 78kg of polyethylene glycol, and fully stirring to ensure that polyethylene glycol is dispersed in water; adding 60kg of oil soluble resin and sulfonated gilsonite, adding linker, controlling temperature to be 90 to 100 DEG C, and keeping constant temperature for 1 hour; placing materials, drying and crushing; and mixing and stirring crushed substance, mica powder, plant fiber and carboxy methylated cellulose (CMC) in a mass ratio of 3:1.5:1:0.5. The high-temperature salt-resistant viscosity reducing filtrate reducer has the advantages of temperature resistance and salt resistance; and fluorescent display is avoided.