Abstract: The static soften behavior of a bridge weathering steel within the interval of passes was investigated with double-pass compression method using MMS-300 thermal-mechanical simulator. The influence of temperature and interval time was analyzed and the softening percentage of static recrystallization under different conditions was defined by the 0.2% stress offset method. The results showed that the static recrystallization occurs after the first pass compression deformation of 5~10 seconds, deformation temperature and interval time have a significant effect on the static recrystallization behavior, and the higher the deformation temperature is, the faster static recrystallization proceeds. The static recrystallization activation energy of weathering steel is about 190.57 kJ/mol and the static recrystallization dynamics model is described.