A preparation method for lithium battery lithium cobalt oxide positive-electrode slurry. Uniform dispersion of various components of slurry within a relatively short period of time is achieved by using the steps of powder dispersing, high-viscosity stirring, low-viscosity stirring, viscosity testing, vacuum defoaming, and the like. The prepared slurry is desirable in uniformity and excellent in stability; meanwhile, the adhesive power of a prepared battery pole piece is improved, so that the consistency and the electrochemical properties of the battery are improved. The preparation method has the advantages of short preparation time, small equipment abrasion, low energy consumption in production, good dispersion effect, and the like. The lithium battery that is prepared from the lithium battery lithium cobalt oxide positive-electrode slurry prepared by using the method is not easy to heat, and is low in internal resistance, high in energy density, desirable in cycle performance, and long in service life.