The invention belongs to the technical field of deep wells and super-deep wells and discloses a lubricant fatty alcohol derivative for a drilling fluid and a preparation method of the lubricant fattyalcohol derivative. The lubricant is prepared from the following raw materials in parts by weight: 20-30 parts of fatty acid, 40-50 parts of fatty alcohol polyoxyethylene ether, 1-5 parts of a catalyst, 15-20 parts of boric acid, 3-10 parts of an emulsifier and 20-30 parts of a dispersant. The derivative has good temperature resistance, is capable of enduring a temperature of 150 DEG C or greaterwith a single dosage, is also capable of enduring a temperature of 150 DEG C or greater after being added into a drilling fluid system, has good dispersity and intensive adsorption, can be uniformly dispersed into a system, meanwhile, is capable of forming a uniform adsorption oil membrane on a well wall or the surface of a drilling tool, is capable of reducing friction resistance of the drillingtool and the well wall, has a good function of preventing drill mud drums, plays a role of increasing drilling speeds, has good compatibility, is applicable to diluted slurry and saline slurry, and iswide in application.