Abstract: The four basic grammatical rules existing in the image language of the Eurasian grassland swan rock painting determine its three characteristics, namely two basic types of swan image, digital "7" original image and free form.The main body of the Eurasian grassland swan rock painting is a combination rock painting, whose meaning is generated in relation to other graphics.In combination with other graphics, the swan image shows some salient features of the swan image, such as the "7" shape, the combination arrangement, the collocation diversification and other foreground effects; on the other hand, it shows the meaning—the sacred bird that is connected with the Cygnus and the Big Dipper.The swan image with this meaning is the original image of the symbol "十" and "卐".A large number of myths and legends, astronomical archaeology, religious, ethnic and folklore literatures, and archaeological discoveries centered on rock paintings have proved that swan worship is a long-standing belief in the Altai languages of the Eurasian grassland, and the swan rock painting is the living fossil carrying the belief.