Abstract: A polymer injection method and apparatus for blocking piping in dikes and dams, uses non-water reacted two-component polymeric material to produce a hydra-insensitive expanding polymer for blocking piping channel. A transferring device is provided to the method, which includes an injection gun, an injector, and a hollow tube, wherein the injection gun connects with an entrance end of the hollow tube through the injector, and an outlet end of the hollow tube inserts into the entrance of the piping channel. The two components of the polymeric material are respectively transported to the injection gun, and are mixed and injected from the gun with high pressure, through the injector, to the hollow tube, and then pushed into the piping channel. Under the chemical reaction, the mixed material expands inside the receiver and becomes foamed solid from liquid, and then the polymer receiver inflates and blocks the piping channel quickly.