Concrete square piles are mostly used in the pile foundation of the old high pile wharf. After long-term operation，the pile foundation generally has different degrees of damage defects，which seriously threaten the safety and durability of the structure and affect the normal use of the wharf. It is urgent to repair and reinforce the damaged pile foundation. At present，the repair and reinforcement of concrete square pile usually adopts such measures as pasting carbon fiber cloth，increasing pile cap，local outsourcing，steel hoop，glass fiber sleeve，etc.，which have achieved good engineering results. This paper discusses the specific implementation scheme，characteristics，key points and applicable conditions of each measure to provide reference for reasonable selection. The application results show that in view of the damage defects of prestressed concrete square piles of the old high pile wharf，according to different damage characteristics and construction conditions，the reasonable selection of repair and reinforcement measures can meet the safe，reliable，economic and reasonable maintenance requirements.