Taking plant mountain blue as raw material, microwave solvent assisted extraction of red pigment. The extraction process was optimized by single factor experiment and orthogonal experiment, and the red pigment fraction was preliminarily purified by column chromatography. The results showed that the microwave power was 300 W, the ratio of material to liquid was 1:40 (m /V), the extraction temperature was 60 °C, and the extraction time was 9 min. The optimum conditions for microwave extraction of sapphire red pigment were obtained. The extraction rate was 0.323%. The mulberry red pigment has an inhibitory effect on Escherichia coli, Bacillus subtilis, Candida albicans and Staphylococcus aureus, and the minimum inhibitory concentrations are 500, 400, 700, 500 mg L -1 , respectively.