Abstract: In order to distinguish from the traditional mapping method suitable for sedimentary area, the researchers have widely used "volcanic structure-volcanic lithofacies-volcanic lithology" trinity mapping method in the continental volcanic rock area of China since the 1990s, and have made important progress. This paper discussed the applicability of this mapping method in the 1:50000 Sumdo geological mapping program for plateau area of Cenozoic volcanic rocks. Combined with remote sensing images and measured section, the authors divided the volcanic facies by field geological and microscope observation, thus restoring the basic framework of the ancient volcanic and retracing the volcanism process. The establishment of Sumdo Cenozoic volcano edifice provides new evidence of regional unconformity between Linzizong volcanic rocks and underlying strata, which further limits the starting time of the India-Asian continent collision.