A cook-off resistant high-energy booster explosive based on hexanitrohexaazaisowurtzitane (CL-20) and 1,1-diamino-2,2-dinitroethylene (FOX-7) was prepared by the solvent-slurry process with ethylene-vinyl acetate copolymer (EVA) and acrylate rubber (ACM) as binders. Small-scale cook-off test was used to select formulations that have cook-off resistant ability and their performance were further compared. Scanning electron microscopy (SEM) was utilized to characterize the morphology and particle size of CL-20, FOX-7 and molding powders. The mechanical sensitivity, thermal decomposition performance, and detonation velocity of the CL-20/FOX-7 boosters were also measured and analyzed. The results showed that the mechanical sensitivity of CL-20/FOX-7 boosters was significantly lower than those of CL-20 based PBX without FOX-7. The maximum measured detonation velocity of the booster is 8576ms(-1). These combined properties indicate that CL-20/FOX-7 booster can be used as an insensitive booster.