The invention relates to a method for preparing a new gynecological anti-bacterial anti-inflammatory drug, namely dithiazole vaginal effervescent tablet and a method for quality control. The dithiazole vaginal effervescent tablet is used for treating gynecopathy, anorectal diseases and skin commonly-encountered diseases such as pelvic inflammatory disease, cervical erosion, vaginitis and the like caused by anaerobic bacteria, aerobic bacteria, trichomoniasis, pure or mixed fungal infections. The dithiazole vaginal effervescent tablet is characterized in that lactic acid and a calcium lactate buffer system are added to the formulation so that the pH value of the drug is between 3.5 and 4.0 similar to the vaginal physiological pH and is advantageous to remove pathogen and infusorian, provide living conditions suitable for vaginal beneficial bacterium group of lactic acid bacteria, and promote the illness rehabilitation. Besides, the dithiazole vaginal effervescent tablet uses pharmaceutical acceptable water-soluble polymer materials such as water-soluble polymer polyethylene glycol, polyvidone K30 and the like to enwrap acidic or alkaline components of an effervescent disintegrant so as to avoid the occurrence of hidden spots or even collapsing phenomenon on the surface of the tablet caused by gas production reaction resulted from small amount of water in the storage process, and uses a ethanol solution with adhesives and surface-active agents for granulation so that the hydrolysis of clotrimazole can be prevented, the infiltration of moisture is promoted in use, the uniform collapse is accelerated, and gas bubbles are homogeneous and stable.