Based on data from BeiDou ground-based augmentation monitoring station in Shaanxi province,a Shaanxi regional ionospheric total electron content(TEC) model is established using the fourth-order spherical harmonic function to generate regional TEC grid products.The experimental results show that the accuracy of the Shaanxi regional ionospheric products obtained from BDS-3 data is 2.54 TECu,which is comparable to the nominal accuracy of the Global Ionospheric Map(GIM) product of the Center for Orbit Determination(CODE).In terms of single frequency precise point positioning(SF-PPP) performance,the BDS-3 regional ionospheric product improves the positioning accuracy by 35%,which is better than the correction performance of the CODE global ionospheric product(27%).Overall,the BDS-3 single system has superior performance in regional ionospheric modeling.