A high performance liquid chromatographic(HPLC) method was developed for the simultaneous detection of eight synthetic dyes in hair dyes.The samples were initially extracted with methanol,then separated on an XB-C18 column with acetonitrile and 0.02 mol/L ammonium acetate solution as mobile phases,and detected with DAD.The best detection wavelengths for HC Red No.3,HC Yellow No.4,HC Orange No.1,Disperse Violet 1,Disperse Black 9,HC Yellow No.2,HC Blue No.7 and HC Red No.1 are 240,410,240,240,240,240,450,270 nm,respectively.The external standard calibration curves were used for quantitative analysis.The calibration curves for 8 dyes were linear in the range of 0.5-100.0 μg/mL with correlation coefficients not less than 0.999 3.The limits of detection were 0.70 mg/kg for HC Red No.3,HC Yellow No.4,HC Orange No.1 and Disperse Violet 1,and 2.50,0.60,0.35 and 0.50 mg/kg for Disperse Black 9,HC Yellow No.2,HC Blue No.7 and HC Red No.1,respectively.The spiked recoveries were in the range of 85.4%-99.8% with relative standard deviations（RSDs,n=6） of 1.1%-3.6%.The precision,accuracy,mean recoveries and the matrix effects were satisfied for the requirements of cosmetic sample measurement.The proposed method was applied in the determination of 8 dyes in actual samples.The method is quick,easy,effective,sensitive and accurate,and could meet the requirements for the determination of eight synthetic dyes in hair dyes.