Despite tremendous breakthroughs in achieving superb electromagnetic interference shielding effectiveness (EMI SE), previous shielding materials cannot be arbitrarily reedited, reshaped, or self-healed once formed. Herein, a hydrogel-type shielding material incorporating a reduced graphene oxide (RGO)-constructed porous conductive network is fabricated through a biomineralization-inspired strategy. The resulting hydrogel exhibits excellent stretchability and durability, remarkable arbitrary shape adaptability and adhesiveness, and an instantaneous self-healing capability. Moreover, an exceptional SE of 90.63 dB and a low SE reflection of 6.41 dB can be simultaneously achieved at a RGO content of 4.76 wt%, which is significantly superior to that of synthetic materials produced to date. This outstanding SE of the RGO-hydrogel is well preserved even after thousands of repeated stretching and self-healing cycles and under extreme conditions. The prominent synergistic effect of conductive RGO network, embedded water, and porous architecture is proven to be the key to such superb shielding performance. Besides, the hydrophilic polymer chains can change the water state and partially activate water molecules, further facilitating electromagnetic wave attenuation. The versatile macroscopic assembly of reshaping and self-healing hydrogels and the ingenious combination of porous conductive framework, hydrophilic polymer chains and polar molecules provide a novel strategy for fabricating superb EMI shielding materials.