The fluororubber F2314 served as the binder; while, nano-LLM-105 acted as the insensitive agent. The DAP-4@LLM-105 energetic composites were prepared by coating with different contents of nanoscale LLM-105 using the solvent evaporation method to improve the safety performance of DAP-4. The morphologies, structures, and thermal properties of the DAP-4@LLM-105 energetic composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC), respectively. Additionally, the sensitivities were tested and analyzed. The combustion performance was also evaluated. The results show that the crystal structures of DAP-4 remain unchanged. When the content of LLM-105 is 20% by mass, the surface of DAP-4 can be uniformly and densely coated. Nanoscale LLM-105 could promote the thermal decomposition of DAP-4. The amount of nano-LLM-105 significantly influences the impact sensitivity and electrostatic sensitivity of DAP-4. As the content of nano-LLM-105 increases, the sensitivity of the DAP-4@LLM-105 micro-nano core–shell structures progressively decreases. Furthermore, the combustion time of the micro-nano core–shell structure is extended.