Most of herbal medicine need to be softened before processing.However,the softening endpoint is generally determined subjectively by a worker.The aim of this study is to explore the feasibility of the needle pressure sensor for the detection of the moisture content of herbal materials.Methods:A total of 3 medicinal herbs S.miltiorrhiza,R.officinale,and Rhizoma Atractylodis were divided into 3 groups of large,medium,and small according to their diameters.A pinprick pressure sensor for determining the hardness of Chinese herbs was designed and homemade.The hardness and moisture content of herbal materials were detected using the pressure sensor and a microwave moisture analyser,respectively.The accuracy of of moisten end point time was verified by human judgment.Results:There was a good linear relationship between moisture content and hardness for Radix Salviae Miltiorrhizae,Radix et Rhizoma Rhei,Rhizoma Atractylodis.Generally,reaching the softening end point took a longer time when the herb diameter was larger.The hardness of herbal materials at the softening endpoint was calculated using the value of moisture content.The needle pressure sensor was applied to determine the softening endpoint time of herbal materials with a high softening percentage ranging from 95.2% to 100% in all groups.Conclusion:The needle pressure sensor can accurately detect the softening condition of herbs.