The dynamic recrystallization (DRX) behavior of fine-grain TC4 titanium alloy prepared by continuous variable cross-section recycled extrusion during hot working was investigated by combining experiment and finite element simulation. The critical strain and DRX dynamic models of fine-grain TC4 titanium alloy were established based on the true stress-strain curves obtained by the experiment. The material properties were defined based on the DRX models, and the thermal compression process was simulated by DEFORM-3D software. The results show that the DRX behavior of fine grain TC4 is significantly affected by thermal compression processing parameters; the volume fraction of dynamic recrystallization (XDRX) and the grain size are increased with increasing deformation temperature and decreasing strain rate; the equivalent strain and range of the deformation zone are increased simultaneously with increasing strain; the correlation between the experimental value and the simulated value of XDRX is 0.9762, which indicates the high accuracy of the established model.