The aim is to establish a method for simultaneous determination of 6 components in water-soluble vitamin freeze dried powder for injection.HPLC method was adopted.The determination was performed on Intersil 5μ ODS2 column with mobile phase A of 0.1% phosphoric acid solution of 0.005mol/L sodium pentanesulfonate and mobile phase B of 0.1% phosphoric acid solution of 0.005 mol/l sodium pentanesulfonate-acetonitrile(20:80, V/V, gradient elution) at the flow rate of 0.9ml/min.The detection wavelength was set at 210 nm, and column temperature was 40°C.The sample size was 20μl.The linear range was 0.2271-0.6812mg/mL for sodium L-ascorbate(r=0.9992), 0.08104-0.2431 mg/mL for nicotinamide(r=0.9998), 0.0098-0.0294 mg/mL for pyridoxine hydrochloride(r=0.9998), 0.03314-0.09942mg/mL for sodium pantothenate(r=0.9999), 0.006193-0.01858mg/mL for thiamine mononitrate(r=0.9998) and 0.009751-0.02925 mg/mL for riboflavin sodium phosphate(r=0.9998), resp.RSDs of precision, stability and repeatability tests were ≤1.60%.Average recoveries were 100.08%(RSD=1.54%, n=9), 99.70%(RSD=1.28%, n=9), 100.38%(RSD=1.13%, n=9), 100.47%(RSD=0.87%, n=9), 100.51%(RSD=0.70%, n=9) and 100.39%(RSD=0.64%, n=9).The method was specific, rapid, accurate and sensitive, and could be used for simultaneous determination of 6 components in water-soluble vitamin freeze dried powder for injection.