In this work, fatigue crack propagation experiment of commercial pure titanium TA2 under different load levels after heat treatment is carried out considering the degree of plastic deformation of crack tip, the adaptability of heat treatment state to different stages of fatigue crack growth. Results show that heat treatment has different effects on the fatigue crack growth rate under different loading conditions. The decrease of fatigue crack growth rate with heat treatment in loading A condition is due to the reduction of the effective load near the threshold region and the increase of the near threshold value. Heat treatment in loading B condition has little effect on the effective load and the plastic deformation of crack tip. The plastic deformation of crack tip is restricted after heat treatment under loading C and D conditions, which leads to the decrease of fatigue crack growth rate.