This invention discloses a method for evaluating the overall symmetry of a face, which is suitable for evaluating the symmetry of a face of a user. The method comprises the steps: shooting the face of the user by using a stereo imaging unit to obtain a stereo image data； calculating a plurality of first asymmetry indexes and a plurality of second asymmetry indexes by a processing unit according to the stereo image data, wherein the first asymmetry indexes are respectively correlated with a plurality of landmark points, the second asymmetry indexes are respectively correlated with a plurality of landmark point groups, and each of the landmark point groups comprises two paired landmark points； and calculating an overall face asymmetry index by the processing unit according to the first asymmetry indexes and the second asymmetry indexes, wherein the overall face asymmetry index is positively correlated with the first asymmetry indexes and the second asymmetry indexes.一種評估顏面整體對稱性的方法，適於評估一使用者的一顏面的對稱性，該方法包含：一立體成像單元拍攝該使用者的該顏面而獲得一筆立體影像資料；一處理單元根據該立體影像資料計算出多個第一不對稱指數及多個第二不對稱指數，該等第一不對稱指數分別相關於多個界標點，該等第二不對稱指數分別相關於多個界標點組，該等界標點組的每一者包含成對的二界標點；及該處理單元根據該等第一不對稱指數及該等第二不對稱指數計算出一整體顏面不對稱指數，該整體顏面不對稱指數與該等第一不對稱指數及該等第二不對稱指數為正相關。
