In order to investigate the nucleation and growth of after-forging static recrystallization of low-pressure rotor steel 26Cr2Ni4MoV, the thermo-torsion experiment was conducted at 900°C,1000°C and 1100°C, respectively. The outer deformation of the used specimens was 0.21. The specimens were kept under a certain temperature for different periods. Results show that the recrystallization grain grew slowly at 900°C and the grain size became even after 30 minutes. The sizes of most grains were almost constant and only several grains grew bigger after 60 minutes. When the specimens were kept at 1000°C and 1100°C for one minute, static recrystallization was completed and the grain size was even. The said research could provide theoretical base for the controlled forging and after-forging heat treatment.