The annotations Du Fu's poetry are voluminous and of high quality,which is a long -held consensus inacademic circles. However, traditional methods of annotating poetry do not meet the needs of modern scholarship. Re-garding Du Fu's Miscellaneous Poems of Qin Prefecture, specifically from the lines " Hesitantly I crossed Long with fear;Boundlessly I reached the Pass with sorrow," if you have knowledge of the Qin-Feng postal route from Fengxiang toQin Prefecture in the Tang Dynasty,you can assert that this poem was not written in Qin Prefecture, but rather in LongPrefecture of Fengxiang District, midway along the postal route. A large number of chapters in this set of poems ob-served from far the military affairs northwest of Qin Prefecture, with the original intention of worrying about the invasionof Tubo (Tibetan Empire). The underlying reason is that Qin Prefecture was the southem barrier of the postal routefrom Longyou Province toward the capital. This paper uses the on-site research method to digitize the Qin -Feng postalroute traveled by Du Fu,and provides explanations for important locations such as "Crossing Long," "Dazhen Pass,"and "Wu Mountain. " There were two postal routes, north and south, from Longyou Province entering the capital. Thenorthern route goes from Lanzhou through Yuan Prefecture,enters Xiao Pass to Chang an, and the souhern route goesfrom Lanzhou via Lin Prefecture,enters Qin Prefecture, and enters Dazhen Pass to Chang 'an. I have digitized the entireroute. This determined the specific route of the most important section of the Silk Road-from Xi'an to Lanzhou.