With rapid developing of intelligent sensing technology, training statistics and competition analysis in sport are becoming particularly important in fairness. Herein, a self-powered and self-healed violation detection system based on an anti-freezing nanocomposites hydrogel (PAGCA) was constructed. The PAGCA was prepared by in-situ polymerization of polyacrylamide in the presence of gelatin and silver nanoparticles decorated carbon nanotubes. Based on a gauge factor of 1.87, the PAGCA-based strain sensor with a self-healing efficiency of 92% can precisely monitor the athletes’ training posture. Additionally, the PAGCA-based triboelectric nanogenerator can work at -30 oC, is able of determining violations, detecting speed and specific position of curling stones, and distinguishing crashes. This work not only provides a smart approach for violation detection in curling competitions, but also demonstrates its promising applications in quick and fair penalties in other sport events, as well as intelligent and digital training for athletes.