Objective: To study the drying shrinkage mechanism of tobacco leaves during the redrying process. Methods: Based on the theory of porous media and elasticity, combined with Fouriers law and Fick's law, the numerical simulation of the thermal expansion, hygroscopic expansion and temperature coupling process in the tobacco leaf drying process was realized. Results: During the redrying process, the maximum stress occurred when the tobacco leaves were dried for about 3 minutes. The moisture stress during the drying process was much greater than the thermal stress; During the low-temperature slow-curing process, the internal moisture evaporation rate of the tobacco leaves was low, so that the shrinkage rate of the tobacco leaves was not high; The shrinkage rate in the drying stage during the redrying process of tobacco leaves was 10%, and the maximum error was 3%. Conclusion: The moisture content is the main influencing factor of the drying shrinkage and deformation of tobacco leaves.