The present invention provides a secondary battery comprising a dry electrical core, the surface of the dry electrical core is coated with at least one layer of an alkali addition metal belt, the alkali addition metal belt comprises an alkali metal active layer, an electron conductor substrate and a first electrode tab, the alkali metal active layer is arranged in the dry electrical core end, theelectron conductor substrate and the alkali metal active layer are stacked together, the first electrode tab and the electron conductor substrate are integrated or connected, and the first electrode tab is connected with the positive electrode tab or the negative electrode tab of the dry electrical core. The present application also provides a preparation method of the secondary battery. The secondary battery can realize the addition of an alkali metal, and finally contributes to improving the cycling performance of the secondary battery.