Construction method for blocking water bags of gravity running water pipeline

The invention provides a construction method for blocking a water bag of a gravity flow pipeline, which is characterized by comprising the following steps of: 1, selecting a well chamber to be blocked; 2, physical exploration is conducted on the well chamber needing to be plugged; thirdly, the well chamber needing to be blocked is cleaned; fourthly, a plugging water bag is manufactured; 5, the plugging water bag is placed in the well chamber on the ground, water is injected into the plugging water bag to enable the plugging water bag to expand, the water head pressure generated by the upstream of the plugging well position is resisted by adjusting the water level height in the plugging water bag, the plugging water bag is made to be tightly attached to the pipe opening of the rain sewage pipeline, and the plugging water bag is made to be tightly attached to the well wall of the well chamber; and 6, after related operation in the target pipe section is completed, the plugging water bag is slowly pumped dry, an