Abstract: A method for preparing an absorbing layer of a solar cell includes the following steps. An absorbing layer precursor containing at least one group XIV element is loaded on a substrate. A solid vapor source containing a group XIV element, the same as the group XIV element in the absorbing layer precursor is provided. The solid vapor source corresponds to the absorbing layer precursor. The solid vapor source and the absorbing layer precursor are kept apart by a distance. A heating process is performed so that the absorbing layer precursor forms an absorbing layer, the solid vapor source is vaporized and generates a gas containing the group XIV element, and the gas containing the group XIV element inhibits the effusion of the group XIV element of the absorbing layer precursor so that the proportion of the group XIV element in the formed absorbing layer is consistent.