In response to the core pain points in emergency rescue scenarios, such as the strong heterogeneity of multi-modal sensing signals, low efficiency of collaborative processing, and insufficient hardware adaptability, this paper reviews the application status of multi-modal sensing technology in emergency rescue fields, analyzes the key issues of the existing signal processing system, and constructs a three-level modular signal processing architecture of “sensing–transmission–pre-processing”. The sensing layer inputs the raw signals and outputs signals in a unified data format; the transmission layer inputs multiple signals, outputs these signals with priority, different paths, and strategies; the pre-processing layer processes the input signals and transmits the information to the unmanned aerial vehicle (UAV) terminal. This research clearly defines the core principles and modular logic of the architecture design, and explores the transmission optimization, resource allocation, and hardware compatibility schemes of different signal types from a technical perspective, demonstrating the balance between the general and specific paths of the architecture. The research results can provide architecture-level design references for the multi-modal sensing module of the airborne-ground integrated emergency rescue UAV, solve the problem of heterogeneous signal collaborative processing, and improve the overall response efficiency and reliability of the emergency rescue system.