In light of the limitations posed by single-detector systems and varying degrees of integration within existing fire warning systems, a rapid fire warning system for new energy vehicles in highway tunnels was proposed. This multi-sensor fusion was used to integrate multiple signals detected during thermal runaway events. The analysis demonstrates that this approach effectively mitigates the issues associated with untimely and inaccurate detection inherent in single-detector setups, while also harnessing the complementary strengths of different sensors. Furthermore, this advanced system enables the implementation of diverse tunnel fire control strategies based on the severity level indicated by warnings. This proactive approach helps prevent secondary disasters resulting from delayed disaster response efforts.