Flexible conductive fibers are essential for wearable electronics and smart electronic textiles. However, in complex operating conditions, conductive fibers will inevitably fracture or damage. Herein, we have developed an elastic conductive self‐healable fiber (C‐SHF), of which the electrical and mechanical properties can efficiently heal in a wide operating range, including room temperature, underwater, and low temperature. This advantage can be owed to the combination of reversible covalent imine bond and disulfide bond, as well as the instantaneous self‐healing ability of liquid metal. The C‐SHF, with stretchability, conductivity stability, and universal self‐healing properties, can be used as an electrical signal transmission line at high strain and under different operating conditions. Besides, C‐SHF was assembled into a double‐layer capacitor structure to construct a self‐healable sensor, which can effectively respond to pressure as a wearable motion detector.