To improve the safety of CL-20, rGO was integrated into CL-20 (CL-20/rGO) by in-situ reduction. The prepared composites were characterized by Scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, High-performance liquid chromatography and Power X-ray diffraction, which proves that the presence/encapsulation of rGO on CL-20 surface would not change the molecular structure, amount and crystal form of raw CL-20. In addition, the thermal stability of the composites has improved, while the mechanical sensitivity was desensitized compared to raw CL-20, suggesting this in-situ reduction could be utilized to improve the safety of CL-20.