Based on the displacement correcting method, the China railway track system(CRTS)Ⅱslab track was modelled in a finite element software. The damage propagation laws of wide and narrow joint separation, mortar-layer separation and supporting-layer cracks during the correction process are studied. The results show that the wide and narrow joint separation would decrease the ability to resist damage of the bonding interface; the mortar-layer separation made little influence on bonding interface; the supporting-layer cracks would grow deeper into the inside of the supporting-layer during the correction process.