A phase diagram of 1,3,3-trinitroazetidine(TNAZ) and 3-amino-2,4,6-trinitroanisole (ANTA) was draw by origin software and the sensitivity, thermal stability, and detonation performance of the eutectic mixture were tested in order to design a potential TNT replacement for melt-cast explosive. The results show that when the weight percent of 3-methoxy-2,4,6-trinitrobenzenamine is 40%, the mixture has the lowest melting point, 84 ℃. The eutectic mixture has good thermal stability and its friction sensitivity, impact sensitivity, electrostatics sensitivity are comparable to TNT. The working capability of the mixture is 148% equivalent to TNT and 114% equivalent to Comp.B. Furthermore, another advantage of eutectic mixture is that there is no permeability oil at 70 ℃ for 6 h. These results indicate that the eutectic mixture is a potential replacement of TNT for melt-cast explosive. 