It was an important step to understand the evolution of urban forms by clarifying the development process of spatial forms over time. In this step, the application of historical maps with rich spatial and temporal information provided an opportunity to increase the objectivity, accuracy, and repeatability of the research. On the other hand, efficient extraction of spatiotemporal information from historical maps as a basis for subsequent analysis remained a common bottleneck in the current time. What could be done to effectively extract urban spatial elements from historical maps? How could spatial elements be translated to obtain quantified data that could be used for spatiotemporal analysis? In this study, we selected historical maps and archival illustrations of the former British Concession area of Tianjin, China, as research materials to explore the extraction and digital translation methods of urban spatial elements for analyzing the evolution of urban spatial form based on historical maps. This method consisted of loading the map, selecting the registration and calibration point, correcting residual, and saving the path of calibration. The study discussed the specific operation of these steps. In addition, based on this method, this paper analyzed the road network, water area, bridges, and gardens in the former British Concession area of Tianjin, China, to verify the feasibility and accuracy of this method. This method was expected to advance the study of urban spatial morphological evolution and its mechanism with rich data of historical maps.