With the support of a vast postal system, the Qing Empire constructed a vertical network of imperial power from the central to local levels. As a centralized state, it needed to overcome the difficulty of controlling distant areas, and thus maintained a tradition of collecting, organizing, supplementing, correcting, and storing information on mileage, with the records of travel and actual operations being interdependent. The postal information in the The Comprehensive Statutes of the Great Qing Dynasty and the "Regulations" mainly comprises three categories: nodes (including origins), routes, and data, which have a complex and consistent structure and pattern, presenting the distribution structure of postal roads in both chain and tree formats. Their centripetal and hierarchical nature reflects the central-to-edge geographic pattern, spatial order, and specific political thinking of ancient dynastic states. Information of road mileage is not only practical data for daily postal work, but also the basis for the state to continuously exercise its transportation power. Given that transportation trades space for time, the relationship between time and space should be emphasized in the study of transportation history. Postal mileage is not only an important indicator of spatial distance, but also the product of the correspondence between time information and geographic information. "Arrival date in the capital" (到京时间)represents the "time can measure the distance" and intuitively reflects the control of transportation over space and time. Postal road space can serve as a reference standard for postal time, and conversely, time is a way of expressing space, summarizing experiences of measurable distance repetition. In actual postal affairs, while mileage remains fixed, operating time varies, making it difficult to maintain the effectiveness of the postal network's dynamic changes and the strength and weakness of imperial power. Traditional postal stations had already expanded and intensified their centripetal force under centralization, but made little progress in terms of time. The timeliness predicament became the most significant obstacle to the rigid Qing postal system in maintaining the established spatial order.