The invention provides a preparation method of a red sage root extract containing 50 to 90 percent of salvianic acid A. The preparation method comprises procedures as follows: 1) the medicinal material of the red sage root is grinded and 0 to 95 percent of ethanol water is added to obtain extracting solution; 2) the extracting solution is concentrated, placed and filtered to obtain filter liquor;3) the filter liquor is processed by an absorptive-resin column and eluted; eluent is thrown off; elution is processed again and the eluent is collected; and the eluent is concentrated to obtain concentrated solution; 4)alkali is used for adjusting the PH value of the concentrated solution to 8 to 12 and the concentrated solution is heated under the temperature of 50 to 95 DEG C and kept for 1 to10 hours; and the PH value of conversion solution is adjusted to 1 to 4; 5) liquor obtained by the procedure 4) is processed by the absorptive-resin column and eluent; the eluent is collected; and the eluent is concentrated to obtain concentrated solution; and 6) the PH value of the concentrated solution obtained by the procedures 5) is adjusted to 4 to 7 and the concentration solution is dried to obtain the red sage root extract. The invention also provides the red sage root extract prepared by the preparation method and a medicine compound containing the extract and pharmaceutically acceptable auxiliary materials.