Concrete plug of diversion tunnel and construction method of concrete plug

The invention discloses a concrete plug of a diversion tunnel and a construction method of the concrete plug and is used for the field of water conservancy projects. The concrete plug of the diversiontunnel comprises a temporary water retaining cofferdam arranged at the front end of the diversion tunnel, and a diversion pipe penetrating the diversion tunnel is embedded into the temporary water retaining cofferdam. The concrete plug of the diversion tunnel is further provided with a plug previous pouring block which can completely block the diversion tunnel. The plug previous pouring block covers the front end of the diversion pipe, the rear end of the diversion pipe is sleeved with a construction gallery, the front end of the construction gallery is connected with the plug previous pouring block, the outer surface of the construction gallery covers a plug body, and the diversion tunnel is completely submerged by the plug body. According to the concrete plug of the diversion tunnel andthe construction method o