The invention discloses a chewable tablet of calcium carbonate dimeticone and a preparation process, belonging to four new national chemical medicines. The preparation of the invention is prepared from the following main components: calcium carbonate, simethicone, siliciidoxydum, aspartame, essence powder, mannite, corn starch, low-substituted hydroxypropyl cellulose and magnesium stearate, wherein the calcium carbonate as the main content has stronger acid-resisting action and rapid and lasting effects, and the simethicone is a foam suppressor for eliminating gastrointestinal tract pneumatosis. The preparation is used for treating peptic ulcers including stomach and duodenal ulcer and easing various uncomfortable symptoms caused by hyperacidity.