To study the change of different processing methods on salvianolic acid B in Radix Salviae Miltiorrhizae.Methods:The preparation of fried Radix Salviae Miltiorrhizae,Radix Salviae Miltiorrhizae charcoal,rice fried Radix Salviae Miltiorrhizae,wine Radix Salviae Miltiorrhizae and vinegar Radix Salviae Miltiorrhizae were carried out respectively.Subsequently,high-performance liquid chromatography was used to detect salvianolic acid B in various processed products of Radix Salviae Miltiorrhizae.Results:The content of salvianolic acid B in the processed products of wine Radix Salviae Miltiorrhizae was the highest,and that of vinegar Radix Salviae Miltiorrhizae was the second.According to the order of vinegar salvianolic acid B content from high to low was Radix Salviae Miltiorrhizae,rice fried Radix Salviae Miltiorrhizae,fried Radix Salviae Miltiorrhizae and Radix Salviae Miltiorrhizae charcoal.Conclusion:The thermal stability of salvianolic acid B is poor,and the thermal stability of salvianolic acid B can be increased to some extent through ethanol and acidic additives,which is worthy of clinical attention.