Flexible wearable sensors have attracted significant interests and created high technological impact on human health monitoring, environmental pollutant detection and bimolecular identification. For sensors, the choice of sensing materials is a crucial priority. As a rising star in the family of two-dimensional materials, MXenes has metal-like electrical properties, adjustable surface chemical property, hydrophilicity and excellent mechanical properties, making them attractive for building different high-performance sensors. This study provides a comprehensive overview of recent advances in MXene-based sensor technology. The synthetic methods and basic properties of MXenes are first briefly introduced. The representative research progresses in MXene-based pressure sensors, strain sensors, gas sensors and electrochemical biosensors are then presented. Finally, the main challenges and future prospects of MXene-based materials in wearable sensor applications are discussed.