The invention relates to a Baicao expandable vaginal suppository for clearing gynecologic inflammation, and a preparation method and a detection method thereof. The expandable suppository comprises a traditional Chinese medicine composition, a matrix and an expansion carrier. The traditional Chinese medicine composition and the matrix form a medicine-containing matrix, which is coated on the surface of the expansion carrier. The traditional Chinese medicine composition is prepared from sophora root, the tuber of stemona, Fructus Cnidii, agrimony, Folium Callicarpae Formosanae, alum, borneol, camphor and boric acid; and the medicine-containing matrix includes an acidifier and hydrogenated lecithin, which cooperate to promote absorption of the traditional Chinese medicine composition. The expandable vaginal suppository is prepared into an osmotic pump expandable vaginal suppository, which has the function of zero level slow release, so as to fully play the therapeutic effect of the expandable suppository. And the Baicao expandable vaginal suppository employs seven unique technologies, and has the beneficial effects of prevention of outflow liquid, high stability, lasting effect and prevention of secondary infection.