Microstructure evolution and deformation stored energy change of sintered pure tungsten during multi-directional forging was investigated by OM and DSC. The source of deformation stored energy and dynamic recrystallization behavior of pure tungsten were studied with XRD and EBSD. The results indicate that dynamic recrystallization during hot deformation leads to remarkably grain refining with porosity significantly reduced. High-density dislocation structure retained in the grain and subgrain result in an increase in deformation stored energy after deformation. There are quantities of recrystallized grains distributed along the higher energy zone in grain boundaries and grain boundary Intersection. The mechanism of dynamic recrystallization is the mixture of deformation induced grain boundary migration mechanism with subgrain coarsening and grain mechanical fragmentation. The recrystallization temperature of pure tungsten unchanged substantially with thermal stability increased after multiple direction forging.