The invention provides a salvia miltiorrhiza soft capsule and a preparation method thereof. The salvia miltiorrhiza soft capsule is prepared from salvia miltiorrhiza extract, polyethylene glycol 400, glycerin, propylene glycol, sodium pyrosulfite, sorbitol and polyethylene glycol 600. The invention aims at the disadvantageous procedures in the conventional salvia miltioorrhiza extraction process,a large number of tests are carried out aiming at overcoming the influence of light and heat on the unstable effective ingredients, thereby avoiding the great loss of the effective ingredients and finally realizing the novel process for preparing medicine liquid by using the salvia miltiorrhiza extract to directly mix with appropriate auxiliary material to obtain the novel salvia miltiorrhiza soft capsule with high effective ingredient content, fast effectiveness and good stability; and meanwhile, the energy consumption during production is reduced, and enormous social benefit is brought.