Abstract: Through the analysis of strength,meso-structure and crack coalescence mode of rock corroded by different chemical solutions,the corrosive and damage charateristics of rock strength,meso-structure and crack coalescence mode are studied.It is known that the material properties of rock skeleton part are worse and the void ratio increases when the rock specimen with multi-preexisting cracks is corroded by chemical solutions.For fracture rock,the fracture stress will be reduced and the crack length will increase under the chemical corrosion.The fracure criterion of rock,with multi-preexisting cracks under the chemical corrosion is proposed considering the reduction of fracture stress and the increment of crack length caused by chemical damage.