Alkali adding method capable of flexibly adjusting concentration of alkali liquor

The invention relates to an alkali adding method capable of flexibly adjusting the concentration of alkali liquor, which comprises an alkali liquor preparation station for supplying the alkali liquor, and also comprises a diversion trench for receiving the alkali liquor from the alkali liquor preparation station through a first pipeline, receiving desalted water through a second pipeline and mixing the alkali liquor and the desalted water in proportion to obtain diluted alkali liquor with specific concentration; the alkali liquor storage tank is internally provided with a partition plate capable of dividing an inner cavity of the alkali liquor storage tank into an upper cavity body and a lower cavity body which are relatively independent up and down, the flow guide groove is communicated with the upper cavity body, the upper cavity body is connected with the lower cavity body through a diluted alkali liquor conveying pipeline, and an output port for outputting diluted alkali liquor is formed in the bottom of