Cao Yu is one of China's leading playwrights,with classics such as Thunderstorm,Sunrise,Field,Peking Man and Home.The poetry in Cao Yu's classic plays has been the focus of academic re-search,and the image research directly related to it should not be ignored.If we can give the definition of universal image,natural image and human image to Cao Yu's classical plays,then,studying the artistic techniques of symbols,hints,metaphors,renderings,unity of opposites,concatenation of simple meanings and superposition of double meanings in classic plays of Cao Yu seems to be helpful to better understand Cao Yu's understanding of fate and the world around him,and can also understand the unique artistic charm of classic plays of Cao Yu more effectively.