The broad-spectrum antimicrobial, extract minimum inhibitory concentration (MIC), bactericidal concentration (MBC) of the galangal extract were studied by Oxford cup method and double dilution method. This paper compared the minimum inhibitory concentration of the galangal extract with common food preservative sodium potassium sorbate’s, benzoic’s, meanwhile, the stability of galangal extract was studied through effects of light, temperature, pH, salt, sugar concentration. The results indicated that: the order of extracts antibacterial activity was as Staphylococcus aureus > Bacillus cereus > parahaemolyticus > Bacillus thuringiensis > B. Subtilis > Salmonella > Shewanella > E. coli. The Bacillus cereus MIC was 0.012 5 mg/mL, Staphylococcus aureus MIC was 0.098 mg/mL, E. coli MIC was 1.56 mg/mL, potassium sorbate MIC was 2.5 mg/mL, sodium benzoate MIC was 25 mg/mL. The test on stability studies of galangal extract has strong stability on pH, salt, sugar and temperature, while is unstable on UV light. Galangal extract has a wide range of antibacterial spectrum antibacterial. The antibacterial activity of galangal extract is stronger than potassium sorbate, sodium benzoate which is expected to become a new generation of green preservative.