Developing comfortable, protective, and reliable monitoring wearable devices is of great significance for next‐generation electronic devices. However, previously reported fabrics have proven inadequate for cross‐mechanism sensing integration and electromagnetic wave (EMW) protection. To address these, an electromagnetic wave‐absorbing flexible wearable device with multimodal sensing capabilities is fabricated based on cotton fabric through polypyrrole (PPy) in situ growth as well as dip‐coating with polyaniline hollow microspheres (PHMs) and amino silane modified polyurethane. It demonstrates excellent electromagnetic wave‐absorbing properties (Reflection loss peak: −48.20 dB, Effective absorption bandwidth:4.2 GHz). Remarkably, three sensing units have been all integrated by a multimodal sensing principle (strain, temperature, and triboelectric nanogenerator) in an all‐in‐one structural configuration. The motion sensing unit shows quick response (225 ms) and recovery (285 ms) times with high sensitivity (Gage factor ≈9.2). The temperature sensing unit has a sensitivity of 0.59% K−1. The self‐powered tactile sensing unit exhibits high output voltage (41 V), maximum instantaneous power density (1.9 W m−2), and detects touching incentive within 0.3 s. Smart human–machine interaction is demonstrated in applications like morse code, temperature, and touching detection. This study serves as a proof‐of‐concept for new smart textiles, showcasing potential for integrated flexible wearable devices, artificial intelligence, and human–machine interactions.