Dry ion-conducting elastomers (ICEs) are emerging stretchable and ionic conductive materials that are demonstrated with excellent thermal stability and great promise in multifunctional iontronic devices. Nevertheless, the poor interface between the ICEs and the dielectric material is one of the issues hindering the application of the stretchable iontronic device. Herein, a polydimethylsiloxane (PDMS) based ion-conducting elastomer with dynamic crosslinking structures is reported, which achieves the stretchability of 475% and healing efficiency of 99%. More importantly, a robust interface bonding can be generated between the electrode and the dielectric material, which is beneficial to enhance the performance and lifespan of the flexible iontronic devices. Using this PDMS based ICE as the electrode and PDMS as the dielectric material, two stretchable iontronic devices (triboelectric nanogenerator and capacitive pressure sensor) are realized with overall self-healing and stretchable capabilities. These findings provide a promising strategy to achieve integrate stretchable iontronics or electronics with a robust interface between the electrode and dielectric materials.