Drilling fluid lubricant composition and preparation method thereof and water-based drilling fluid and application thereof

The invention belongs to the technical field of drilling fluid for the petroleum and natural gas industry, and relates to a drilling fluid lubricant composition and a preparation method thereof and awater-based drilling fluid and application thereof. The lubricant composition comprises modified vegetable oil, biodiesel, capsule particles, a first dispersant, an extreme pressure antiwear additiveand a defoaming agent, the capsule particles comprise internal materials and capsule materials covering the internal materials, the capsule materials are made of phenolic resin, and the internal materials include sulfonated polyimides, water and a second dispersant. The capsule particles are introduced to the drilling fluid lubricant composition, so that the composition in the drilling fluid is not affected by high temperature, is easy to degrade, has good cloud point, has low influence to rheological property of the drilling fluid, and can meet requirements on lubricating property of the drilling fluid better. 本发明属于石油