The invention relates to cooling liquid for diamond wire cutting technology, which mainly comprises a lubricant, an emulsifier, an antirust agent, a dispersant, a preservative, and deionized water, wherein the mass percents of the components are 5-50% of the lubricant, 0.05-10% of the emulsifier, 0.1-5% of the antirust agent, 0-10% of the dispersant, 0-5% of the preservative, and the balance being deionized water. The cooling liquid has excellent lubricity and dispersibility, is easy to clean, suitable for cutting of hard and brittle materials such as crystal silicon, sapphire, and the like, can not only meet requirements for diamond wire high-speed cutting, but also realize good surface finish of cut pieces, and can significantly increase product qualified rates.