A novel HPLC-MS method was established, using a synthesized rhodamine B hydrazide (RBH) as the new pre-colunm derivatization reagent. After extracted with methanol and derivatized with RBH, the samples were determined by high-performance liquid chromatography(HPLC) coupled with mass spectrometry(MS). The results showed that the reagent RBH has a good sensitivity for mass spectrometry detection, and the derivatization reaction of benzaldehyde was efficient and specific. The benzaldehyde showed a good linear relationship in the range of 0.05～6.00 ng/mL, and the correlation coefficient was 0.996 2. The detection limits and quantitation limits of the method were 0.80×10^-3 ng/mL and 2.71×10^-3 ng/mL, respectively. The standard recovery rate was 93.3%～104.0%, and the relative standard deviation was 0.8%～2.6%. The method was high selectivity and high sensitivity, and suitable for the determination of benzaldehyde residues in honey.