Cellulose-based flexible sensors, characterized by outstanding biocompatibility, degradability, and rich surface chemistry, offer considerable promise for human health monitoring. Limited extensibility, however, predisposes these materials to mechanical damage like cracking, which compromises sensor stability. Integrating self-healing functionalities not only restores their mechanical and sensory performances but also prolongs their service life. This paper reviews the diverse self-healing mechanisms of cellulose-based sensors and examines the contributions of dynamic bonding to reconciling self-healing prerequisites, efficiency, and mechanical integrity. The discussion extends to the latest advancements in cellulose-based flexible self-healing sensors for tracking health indicators, including movement, body temperature, sweat, and respiration, while also contemplating their prospects and emerging challenges.