To simply and efficiently prepare high-purity crocetin from gardenia yellow pigment,the alkaline hydrolysis process was optimized using an orthogonal experimental design.High-performance liquid chromatography (HPLC) was established for the determination of crocetin in the samples.The evaluation index was based on the purity and yield of crocetin.The solid-liquid ratio,NaOH concentration,hydrolysis temperature,and hydrolysis time were investigated.The optimal conditions for alkaline hydrolysis of gardenia yellow pigment were obtained as follows:solid-liquid ratio 1∶6 g/mL,NaOH concentration 3 mol/L,hydrolysis temperature 55°C,and hydrolysis time 60 min.Under this condition,the crocetin yield was 15.33%±1.25% and a content of 97.24%±0.78%.Finally,high-purity crocetin was prepared from the gardenia yellow pigment in a single step.This method is simple,environmentally friendly,and suitable for industrial application.