Two methods,high-performance liquid chromatography with diode array detector(HPLC-DAD) and high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) were developed for the determination of synthetic pigments such as tartrazine,sunset yellow,brilliant blue which were illegally added into sweet potato noodles.The crushed samples were extracted by ultrasound for 20 min and vortex blending assisted extraction 2 min in0.25 mL ammonia solution(1∶1,v/v).The HPLC-DAD and HPLC-MS/MS methods were used.The calibration curves of each synthetic pigment showed good linear relationships.The Square correlation coefficients of all pigments were from0.999 2-0.999 3 by HPLC-DAD and from 0.996 1-0.997 9 by HPLC-MS/MS.The determination limits of 3 synthetic pigments were 0.08-0.3 mg/kg by HPLC-DAD and 0.02-0.05 mg/kg by HPLC-MS/MS.The recovery tests were performed at the low,middle and high level with mixed standard solution of 3 synthetic pigments.The recoveries of HPLC-DAD and HPLC-MS/MS were 83.5%-89.9% and 84.2%-92.5% respectively.Meanwhile,the relative standard deviations of HPLC-DAD and HPLC-MS/MS were 0.62%-4.10% and 0.96%-4.92% respectively.The method of HPLC-DAD and HPLC-MS/MS were accurate,sensitive and accurate for validation of positive samples.