Objective: To optimize vacuum-belt drying process parameters of Yangzheng Xiaoji capsules extract. Method: HPLC-ELSD was employed to determine the content of oleanolic acid with mobile phase of acetonitrile-methanol-0.5% acetic acid(20:70:10).Taking water content of dry extract and transport rate of oleanolic acid as indicators

orthogonal design was adopted to investigate effects of feeding speed

belt speed and heating system temperature on vacuum-belt drying process of Yangzheng Xiaoji capsules. Result: Optimal parameters of vacuum-belt drying process were as follows:belt speed of 6 cm·min-1

feeding speed of 12 mL·min-1

heating system temperature at 110 ℃

material temperature of 30 ℃

cooling zone temperature at 45 ℃

initial solid content in extract about 45%

vacuum degree Conclusion: This optimized technology is reasonable and feasible with low water content and good quality

which is suitable for large scale production of Yangzheng Xiaoji capsules.