A rapid quantitative method for the determination of taurine in milk powder by high performance liquid chromatography (HPLC) with ortho-phthaladehyde (OPA) as pre-column derivatization reagent has been developed. After automated derivatization in the autosampler, the standards and samples were directly into the HPLC system for analysis. An Ultimate AQ-C18 (2.1 mm × 100 mm, 3 μm) was used for the analysis at 40 ℃. The separation was carried out using a mobile phase consisting of acetonitrile and 10 mmol/L sodium acetate solution (pH 4.2) at a flow rate of 0.4 mL/min. The linear range of the method was from 5.0 to 100 μg/mL with a correlation coefficient (R2) of 0.999 7. The spiked recovery was in the range of 97.33%–105.74%. At the signal-to-noise ratio of 3 (RS/N = 3), the limit of detection (LOD) was 0.06 mg/100 g and the limit of quantification was 0.2 mg/100 g (RS/N = 10) for taurine. The proposed method proved to be simple and sensitive for routine analysis of taurine in milk powder with good reproducibility.