Abstract: In the actual working conditions, the concrete of the ship lock is affected by the friction and collision of the ship’s hull and the erosion and wear of the ship’s traveling wave during the rising water period, and is damaged by CO₂ in the air during the falling water period. In order to study the performance degradation law of the ship lock concrete under this working condition, the underwater steel ball method was used to approximate the physical wear of the ship lock concrete in the rising water period, and the rapid carbonation test was used to simulate the CO₂ erosion in the falling water period. The duration of abrasion and carbonization, as well as the alternate cycle mechanism, is determined according to the design service index of the lock and the characteristics of navigability. The engineering performance degradation law of the ship lock concrete is reflected by the carbonation depth and anti-abrasion strength, and the composition and pore structure evolution of the ship lock concrete are characterized based on the thermalgravimetric analysis and mercury intrusion porosimetry. The simulation test and analysis show that the abrasion accelerates the carbonization reaction to a certain extent. The mechanism of abrasion and carbonation cycle is consistent with the actual failure of the inland ship lock concrete.