Regenerated liquid drainage structure of catalytic flue gas desulfurization device and catalytic flue gas desulfurization tower

The invention discloses a regenerated liquid drainage structure of a catalytic flue gas desulfurization device and a catalytic flue gas desulfurization tower applying the regenerated liquid drainage structure of the catalytic flue gas desulfurization device, which can control the pressure at the outlet end of a U-shaped liquid seal so as to solve the technical problem of adjusting the liquid storage state of the U-shaped liquid seal as required. Comprising a first drain pipe and a second drain pipe, the upper end of the first drain pipe is connected to the atmospheric environment through a ventilation control valve, and the lower end of the first drain pipe is used for being connected with a regeneration liquid tank; when the ventilation control valve is opened to a set state, a first pressure environment is formed, and the first pressure environment can automatically maintain regeneration liquid which enables the bent structure to form liquid seal in the bent structure communicated with the first liquid disc