Transient electronics have emerged as a promising way to mitigate electronic pollution. However, developing soft transient electronics with practical potential to recover mechanical properties, restore sensing signals during operation, and rapidly vanish under specific external stimulation remains challenging. Herein, a molecular design strategy is proposed based on Zn2⁺-coordinated oxime-carbamate groups to simultaneously enhance mechanical strength, toughness, self-healing, and photodegradation performance in soft polyurethane elastomers (Zn-MDPU). Compared with MDPU elastomers without Zn2+ coordination interactions, the mechanical strength and toughness of Zn-MDPU elastomers are enhanced 3.8- and 16-fold, respectively, without any deterioration in their softness. The Zn2+ ions facilitate both the dynamic exchange of oxime-carbamate units, to enable efficient self-healing at room temperature, and the homolytic scission of weak N─O bonds within these groups for photodegradation. Application of Zn-MDPU elastomers coated with liquid metal is demonstrated through a patterned flexible transient conductor for human–machine interaction and health monitoring, along with the development of a self-healing triboelectric nanogenerator for mechanical energy harvesting. The proposed molecular design strategy opens vast possibilities for developing soft transient materials for wearable electronics applications.