In order to improve the desensitizing efficiency of TATB on HMX, HMX/TATB composites were prepared by in-stiu coating and mixing method respectively. The composite was characterized by SEM, DSC and sensitivity test. Compared with the sample prepared by mixing method, the sample prepared by in-stiu coating with the same TATB content has a better coverage, a higher decomposition temperature of HMX and lower mechanical sensitivity. The impact sensitivity and friction sensitivity of HMX/TATB compounds with 10% TATB prepared by in-stiu coating is 24%, 0% respectively.