The present invention disclosed a method to produce a regenerated fiber bragg grating of Ge-B co-doped photosensitive fiber utilizing CO2 laser annealing. Besides, the present invention also disclosed a CO2 laser annealing system to produce a regenerated fiber bragg grating by utilizing the method invented in the present invention. The CO2 laser annealing system consists of an amplifies spontaneous emission, ASE broadband source, a 3 ports optical circulator, a three-axis positioning stage, a sapphire furnace, a small load, an optical spectrum analyzer, OSA, a cylindrical lens, two convex lenses and a CO2 laser source. The produced regenerated fiber bragg grating has good temperature sustainability up to 1000c