The invention discloses acetylcysteine effervescent tablets and a preparation method thereof and belongs to the technical field of medicines. The acetylcysteine effervescent tablets are prepared fromthe following components in percentage by weight: 20 to 40 percent of acetylcysteine, 20 to 60 percent of an alkali source, 20 to 40 percent of a filling agent, 0.1 to 1 percent of a lubricant, 0.1 to1 percent of a corrigent and 0.08 to 0.1 percent of EDTA (Ethylene Diamine Tetraacetic Acid); the filling agent is one or two of maltodextrin and a beta-cyclodextrin derivative; the beta-cyclodextrinderivative is one or two of hydroxypropyl beta-cyclodextrin and sulfobutyl beta-cyclodextrin; the corrigent is prepared from a flavoring agent and a sweetener; the flavoring agent is orange-flavoredessence; the sweetener is sucralose. According to the acetylcysteine effervescent tablets disclosed by the invention, medical components and auxiliary materials are improved, and one or two of the maltodextrin and the beta-cyclodextrin derivative are used as the filling agent; the acetylcysteine effervescent tablets have relatively good compressibility and a remarkable lubricating effect; the acetylcysteine effervescent tablets are used for radically solving the sticking condition of the effervescent tablets; the product has a good appearance and good stability; a preparation technology has good tolerance and is suitable for large-batch production.