A method for the determination of taurine in amino-acid-hydrolyzed formula milk powder with special medical purpose was developed using a novel derivative way， coupled with two-dimensional liquid chromatography (2D-LC) system on precise quantification. The milk powder matrixes were dissolved with ultra pure water， precipitated proteinaceous substance by potassium ferrocyanide and zinc acetate， derived by high concentration dansylchloride (30 mg/mL)， adjusted by triethylamine on pH value， and heated in 60 ℃ water bath for 1 hour. The derivative was performed on the Agilent XDB-C18 column with methanol and 0.1% trifluoroacetic acid as the one-dimensional LC mobile phase， so as to separate other amino-acids and locate the target. Subsequently， taurine entered into the Thermal AccucoreTM PFP column after the capture and center-cutting by column switching technique， acetonitrile and 0.1% formic acid were utilized as the two-dimensional LC mobile phase to gradient elute the taurine， combined with fluorescence detector on quantification analysis. The derivative parameters (concentration， pH value and time) and 2D-LC condition were optimized to promote the target recovery. Taurine showed good linear ranged from 1.0-20.0 mg/L， while the correlation coefficients(R2) was higher than 0.9996. The average recovery of the actual samples was 95.2%， with RSD 1.86%. This method， with high accuracy and strong anti-interference ability， overcame the influence of other amino acids on target derivation， and improved the derivative efficiency. This method solves the problem that national standard cannot accurately quantify the content of taurine in those milk powder with special medical purpose， and has been recognized by AOAC committee as the recommended method on taurine detection of those milk powder with complicated matrix.