With the approaching exhaustion of shallow-ground gas and oil, heat-resistant explosives are in highly demand in oil/gas ultra-deep and ocean well development. However, the prediction method on decomposition temperatures of heat-resistant explosives is still yet to be determined. In this paper, based on the decomposition reaction of “trinitrotoluene mechanism”, the influences of the enthalpy changes, entropies, Gibbs free energies, conversion temperatures and resonance energies on corresponding decomposition temperatures were studied. A theoretical relation was proposed after a genetic-algorithm optimization. Based on this relation, the decomposition temperatures of LLM-105 derivatives and its isomers were discussed. The results showed that the proposed relation coincided well with the decomposition temperatures of typical aromatic explosives. Furthermore, the decomposition temperatures of LLM-105, LLM-105I2 and ANPZ,TANPyO were predicted high and can be taken as new heat-resistant explosive candidates.