The invention discloses a Metronidazole, Clotrimazole and Chlorhexidine Acetate Effervescent Tablet and the preparation method. Each tablet has the following proportion of contents: metronidazole 0.2 gram, clotrimazole 0.16 gram, acetic acid chlorhexidine acetate 0.008 gram, fumaric acid 0.108 to 0.162 gram, tartaric acid 0.012 to 0.018 gram, solium bicarbonate 0.12 to 0.18 gram, starch 0.02 to 0.04 gram, dextrin 0.003 to 0.007 gram, hydroxypropyl cellulose 0.007 to 0.013 gram, talc 0.01 to 0.017 gram, sodium dodecyl sulfate 0.01to 0.02 gram, and proper proportion of povidone K30 water solution. According to the preparation method, the components are mixed to produce granule (1) and granule (2); the talc, sodium dodecyl sulfate and the granule (1) and granule (2) are mixed uniformly; granule content is tested and according to the granule content, the tablet weight is identified for tabletting. The invention overcomes the shortages with prior art, enables the acetic acid chlorhexidine acetate to perform functions normally, performs synergistic effects of the three drugs, and greatly enhances the cure rate. Besides, the frothing volume is high, and within storage period, the quality is stable and the drug effects are not affected.