In order to study the merits of fiber bragg grating(FBG) sensor in vibration damage identification, an interrogation based on unbalanced M-Z interferometer and PGC is designed. The damage indicator, sum of relative variation ratio, is constructed based on wavelet packet node energy. The principle of statistical process control is introduced and the damage identification process using Xbar-R chart is derived. The vibration signals under health status and six kinds of damage status are measured using FBG interrogation. Results show that the damage indicator can judge the presence of damage, the location of the damage and the quantification of the severity of the damage.