The invention relates to andrographolide ground suspending liquid, a preparation method thereof, and the application of pharmaceutical preparation, which belongs to the field of pharmaceutical preparation. The preparation method comprises the steps of adding andrographolide into hydrophilic accessory solution with certain concentration, and grinding the andrographolide in a basket grinder to prepare suspending liquid with particle sizes smaller than 3000 nm. Liquid layers of pharmaceutical suspending liquid are laminated onto blank pellet cores with certain particle size range, to prepare andrographolide immediate-release pellets. After grinding, by reducing pharmaceutical particle sizes, increasing particle surface areas and improving the wettability of pharmaceutical particles, the dissolution in vitro of the drug is improved, and hydrophilic carriers are adopted to effectively prevent the aggregation of pharmaceutical particles so as to improve the stability of the pharmaceutical preparation. The preparation method is simple and easy for industrialized production, and the dissolving-out speed of the prepared andrographolide immediate-release pellets is high, so that the bioavailability is obviously improved.