Efficient anti-pollution isolation liquid for well cementation and preparation method thereof

The invention relates to an efficient anti-pollution isolation liquid for well cementation and a preparation method thereof, belonging to the technical field of well cementation. The isolation liquid comprises the following components in parts by weight: 100 parts of clear water, 4-29 parts of suspending stabilizer, 0.5-5 parts of fluid loss additive, 0.3-2 parts of tackifier, 0.1-5 parts of diluting agent, 0-5 parts of viscosity and shearing force increasing agent, 30-350 parts of weighting agent, 1-25 parts of pH value regulating agent and 0.1-0.5 part of defoamer. The isolation liquid provided by the invention has wide density regulation range, large temperature resisting range, strong anti-pollution capacity, wide applicability and strong maneuverability, can be conveniently subjected to in-situ preparation, can be prepared by using a mud tank equipment base fluid method or cement vehicle equipment dry-mixing method, and can apply effective abrasion, scraping and carrying effects to attachments on an interface of a well wall; and by using the isolation liquid, the problems that in the well cementation operation, pollution is generated by fluid displacement, the adhering quality of a well cementation interface is poor and the like are effectively solved.