Urban area-of-interest (AOI) refers to an integrated urban functional zone with defined boundaries. The rapid development of urban commerce has resulted in an increased demand for more precise requirements in defining AOIs. However, existing research primarily concentrates on broad AOI mining for urban planning or regional economic analysis, failing to cater to the precise requirements of mobile Internet online-to-offline businesses. These businesses necessitate accuracy down to a specific community, school, or hospital. In this paper, we propose an end-to-end multimodal deep learning algorithm for detecting AOI fence polygon using remote sensing images and multi-semantics reference information. We then evaluate its timeliness through a cascaded module that incorporates dynamic human mobility and logistics address information. Specifically, we begin by selecting a point-of-interest (POI) of specific category, and use it to recall corresponding remote sensing images, nearby POIs, road nodes, human mobility, and logistics addresses to build a multimodal detection model based on transformer encoder-decoder architecture, titled AOITR. In the model, in addition to the remote sensing images, multi-semantic information including core POI and road nodes is embedded and reorganized as the query content part for the transformer decoder to generate the AOI polygon. Meanwhile, relatively dynamic distribution features of human mobility, nearby POIs, and logistics addresses are used for AOI reliability evaluation through a cascaded feedforward network. The experimental results demonstrate that our algorithm significantly outperforms two existing methods.