Solvent/nonsolvent recrystallization method was used to prepare HNS/HMX mischcrystals in order to increase the energy output of HNS-Ⅳ,and its structure characterization and performance were studied in detail. Results show that β-HMX is surrounded by superfined HNS particles in the core. The specific surface area,impact sensitivity,friction sensitivity,and initiaiton energy of HNS-Ⅳ,superfined HNS/HMX(80/20) and superfined HNS/HMX(70/30) are as follows: 14.25 m²·g^-1,9.98 m²·g^-1,9.56 m²·g^-1； 52%,76%,78%; 14%,16%,19%; 0.49 J,0.50 J,0.58 J respectively.