The paper presents the finite element analysis on the stress distribution in lock wall subjected to an impact of ship with the maximum weight, impact angle and velocity. The results reveals that the C25 concrete traditionally used in lock wall can’t carry the tensile and compressive stress at collision. Based on the FEM analysis results, various strength indices of concrete in lock wall are correspondingly suggested. The field tests in actual engineering further verify the reliability of bond strength index between new and old concrete. These proposed indices provide reliable reference for the design and repair of ship lock structure.