Dynamic recrystallization behavior of Ti40 burn-resistant alloy, a highly stabilized β titanium alloy, was researched by hot compression test. The results indicate that the nucleation mechanism of dynamic recrystalization of Ti40 alloy includes subgrain nucleation, initial grain boundary bulging nucleation and dislocation pile-up nucleation. After high temperature plastic deformation, air-cooling and annealing at 850 ℃, the recrystallization grains of the alloy present mixed grain structure. Recrystallization grains grow sufficiently after the alloy is annealed at 1000 ℃, which is whole recrystallization structure.