Addressing the urgent need for mitigating the hazards of Thermobaric Explosives (TBX) in confined spaces, this study develops a multi-stage explosion pressure model incorporating detonation, combustion, and pressure oscillations to support accurate prediction of blast threats. An energy redistribution-based suppression model for water mist is proposed, effectively attenuating explosion energy by converting shock and thermal loads into droplet latent heat and unreacted chemical energy. A dimensionless suppression coefficient is introduced to integrally evaluate the coupled physical and chemical inhibition mechanisms. Experimental results in a sealed explosion vessel demonstrate that water mist significantly reduces the peak quasi-static pressure and temperature, thereby effectively mitigating overall explosion damage, although its effect on shock wave energy remains limited. The suppression performance improves with increased Weber number and water mist mass fraction, yet exhibits clear saturation trends beyond critical thresholds. Importantly, physical and chemical suppression mechanisms contribute equally to explosion mitigation. This research provides theoretical foundations and quantitative tools for enhancing safety protection against TBX explosions and clarifies the mechanism of water mist-based hazard suppression.