The invention discloses melt-cast explosive 3,4,5-trifluoro-2,6-dinitroaniline and a preparation method and application thereof. The structural formula of the 3,4,5-trifluoro-2,6-dinitroaniline is shown as the formula (please see the specifications for the formula). The preparation method of the melt-cast explosive 3,4,5-trifluoro-2,6-dinitroaniline comprises the following step that a raw material1 is nitrified to obtain a target compound, namely the 3,4,5-trifluoro-2,6-dinitroaniline (ZXC-17). Compared with TNT and 2,3,4-trifluoro-1,5-dinitrobenzene, the detonation performance of the 3,4,5-trifluoro-2,6-dinitroaniline is more excellent, the single crystal density is higher and reaches 1.972 g/cm<-3>, impact sensitivity also reaches 62 J, the 3,4,5-trifluoro-2,6-dinitroaniline is high-energy explosive with the melting point being 92.20 DEG C and is quite suitable for serving as melt-cast explosive, a synthesis method is quite simple and convenient, the yield is high, and industrial production is easy; and the 3,4,5-trifluoro-2,6-dinitroaniline compound is insoluble in water, friendly to the environment and easy to recrystallize, and thus the potential industrial value of the 3,4,5-trifluoro-2,6-dinitroaniline compound is higher.