Water stop system for wharf underwater breast wall construction

The utility model provides a waterstop system for wharf underwater breast wall construction, which comprises a breast wall, the breast wall is arranged along a water bank, the breast wall forms a semi-enclosure structure through an existing building, and a coastal side and a coast side are respectively formed on two sides of the semi-enclosure structure; the coastal side is provided with a normal water level, the height of the normal water level is higher than the bottom elevation of the shore side, and a base layer at the bottom of the breast wall is provided with a water seepage gap; the isolating layer is arranged on the coastal side and is perpendicular to the water flow direction, and a transition section is directly formed between the isolating layer and the coastal side; the transition section is provided with an operation platform, and the operation platform is used for connecting the isolation layer and the coast side. Compared with the mode that an isolation layer is directly arranged at the constru