To improve the safety of potassium chlorate in pyrotechnics,the method of liquid phase separation was adopted to coat potassium chlorate. XPS and SEM were used to test the coating results,and ARC,impact sensitivity and friction sensitivity apparatus were used to analyze the safety properties of the coated potassium chlorate. The results show that the coating degree of potassium chlorate by using PVB can be 95.13%; compared with uncoated potassium chlorate,the initial exothermic temperature of coated potassium chlorate is increased by 36.08 ℃,maximal pressure produced by unit mass decreased by 0.63 MPa·g^-1,friction sensitivity decreased by 64%,and impact sensitivity decreased by 72% respectively.