Experiments were conducted to study the underwater explosion performance of emulsion explosives (EE) after hot water bath. Spherical charges of EE with different sensitizers and hot water bath were prepared and tested. As for as-prepared charges, the detonation velocity experiments and underwater explosion experiments were carried out and the crystallization ratio was measured and calculated by the dissolution and neutralization method. The results showed an inverse relationship between explosion parameters (pressure peak, specific impulse, detonation velocity and specific total energy) and heating time. It also revealed that the effective explosive weight of EE was re-duced with long time of hot water bath. Moreover, the crystallization ratio and the decreasing rate of explosion parameters of EE sensitized by NaNO2 were apparently higher than EE containing physical sensitizers (glass microballoon and perlite), which was attributed to the different destruction mechanism of EE. After 6-hour hot water bath, the EE containing physical sensitizers still retained detonator sensitivity and more than 80% of specific total energy. Meanwhile, the crystallization ratio was less than 20%. Whereas, the EE sensitized by NaNO2 lost the detonator sensitivity and the crystallization ratio of EE was also above 40%.