This paper summarizes the maintenance practice of miter gate bottom pivots since the planned overhaul system was implemented in Gezhouba ship lock in 1990.The maintenance cycles of upper and lower miter gate bottom pivots are 18-24 a and 12 a respectively，which can satisfy the normal operation of the bottom pivots.Whether the contact surface of the bearing bush and the mushroom head meets the requirements is an important factor to ensure the safe and reliable operation of the bottom pivots.The bottom pivots of the downstream and upstream miter gates are repaired with the gate body detached or not respectively.The bearing bush and mushroom head of the bottom pivot are processed and repaired by the vertical displacement of the ball center.The diameter of the bearing bush is equal to the size of the mushroom head.The mushroom head does not feature a surfacing layer type.The replacement process is implemented by using carbon arc gouging to disconnect the old bearing bush and install a frozen new bearing bush.The above maintenance process saves costs and shortens the construction period.Adding limited displacement devices can prevent permanent displacement of the bottom pivots due to the ingress of sediment.