To understand the influence of different processing methods on the hygroscopicity of instant tea, this study investigated the physical and hygroscopic properties of instant tea produced by different processing techniques including commercial instant tea and hollow granulated instant tea (industrial production), and different drying techniques including spray drying and freeze drying (laboratory preparation). The investigation encompassed three representative tea categories: instant green tea, instant black tea, and instant jasmine tea. The experimental data were fitted and characterized based on isothermal hygroscopic models which are commonly used. The results showed that the fluidity of hollow granulated instant tea was better than that of commercial instant tea, and its bulk density was significantly lower. The fluidity of freeze-dried instant tea was better than that of spray-dried instant tea, also with significantly higher bulk density and lower moisture content. In terms of hygroscopicity, the higher the water activity, the greater the difference in equilibrium moisture absorption rate among instant teas produced by different processing methods, with hollow granulated instant tea and freeze-dried instant tea showing a lower value. The fitting results of isothermal hygroscopic models indicated that the Ferro-Fontan model could accurately describe the hygroscopic behavior of instant tea produced by different processing methods (R2>0.99). Calculated by the model, the absolute safe moisture content ranges for instant tea produced by different processing techniques and drying techniques at 20°C were 4.00%~4.59% and 3.47%~6.09%, respectively, while the relative safe moisture content ranges were 10.42%~12.12% and 8.54%~12.73%, respectively. In conclusion, the hygroscopicity of instant tea produced by hollow granulation and freeze-drying processes was significantly lower than that of the conventional spray drying process, which provides theoretical reference for optimizing instant tea processing and regulating storage conditions.