Developing lightweight polymer shielding membranes with additional physicochemical properties is of great significance for addressing the complex contemporary security demands. However, precise structural design at the molecular level remains a challenge. Herein, a unique Janus composite membrane is assembled from conductive AgNWs/MXene 1D/2D network and polyurethane elastomer (MPHEA), displaying combined superior electromagnetic shielding effectiveness (EMSE) of up to 80 dB and remarkable infrared stealth capability at a wide temperature range of room temperature to 50 °C. Moreover, the endowed chemical crosslinking in the membrane resulted in the exceptional mechanical strength, self‐healing, and superior adhesion. The maintained electromagnetic shielding (over 20 dB) even under a strain of 40% and the recovered shielding efficiency of 90% after mechanical damage and self‐healing are observed, which is attributed to the synergistic 3D polymer elastic and 1D/2D conductive network in the multi‐dimensional crosslinked MPHEA@AgNWs/MXene composite membrane. This work has represented an excellent micro‐nano structure design strategy on multifunctional electromagnetic wave manager in complex application scenario.