Abstract: In order to simplify the pretreatment of tobacco stem and improve processing quality,the original stem pretreatment by two-step moistening + two-step storing was replaced by stem dipping + microwave moistening.The factors affecting the related parameters for each processing step were optimized through a series of experiments and regression analysis.Comparing with the original one,the improved process flow featured smaller footprint,processing time saving up to 4 hours per batch,better water permeation and stable moisture content in stem,even stem moisture content in transverse cross section in silo,the standard deviation of moisture content in cut stem reduced by 0.07%,the filling power of finished cut stem increased by 0.4 cm³/g and the proportions of long and short strands basically unchanged.The optimal processing parameters are:stem dipping time 70.18 seconds,dipping temperature 52.7℃,microwave power 64 kW and radiation duration 75 seconds.