To develop an analytical method for the simultaneous separation and determination of residual benzoyl peroxide (BPO) and benzoic acid (BA) in flour and wheat products by HPLC.Methods BPO and BA were extracted by ethanol, and separation and determination were carried out on Symmetry C₁₈ column using a gradient mobile phase by HPLC at 235 nm. Results BPO and BA showed good linearity (r>0.999 9) in the range of 0.10-20 mg/L. For BPO and BA, the recoveries were 95.2%-99.5% and 95.3%-106%, respectively; the limits of detection (LOD) were 0.10 and 0.08 mg/kg; the limits of quantification (LOQ) were 0.30 and 0.24 mg/kg.Conclusion The method is simple and reliable for the determination of BPO and BA in wheat flour and its products.