The invention discloses a carbonate spring tablet and a preparation method thereof. The carbonate spring tablet contains 1-10 parts by weight of bicarbonate, 0.1-3.5 parts by weight of organic acid, 0.01-2 parts by weight of a binding agent, 0.005-1 part by weight of a functional additive and 0.005-0.5 part by weight of other ingredients, wherein the functional additive is selected from at least one of a cleaning agent and essence. The carbonate spring tablet can effectively remove residual chlorine, heavy metals and other harmful substances in shower water, and the carbonate spring tablet can take effects of beautifying skin, caring skin, sterilizing and diminishing inflammation, so as to significantly improve the comfort of a bath.