Method for preparing lithium hydroxide solution by extracting lithium from clay lixivium

The invention relates to a method for preparing a lithium hydroxide solution by extracting lithium from a clay leaching solution, which comprises the following steps of: performing impurity removal and homogeneous membrane electrodialysis treatment on the clay leaching solution to obtain a lithium sulfate purified concentrated solution; adding the lithium sulfate purified concentrated solution into a salt chamber of a three-chamber membrane electrolytic cell; respectively adding sulfuric acid and lithium hydroxide with preset concentrations into an acid chamber and an alkali chamber of the three-chamber membrane electrolytic cell; a direct-current power supply is introduced into the three-chamber membrane electrolytic cell for electrolysis to obtain the lithium hydroxide solution, so that the whole preparation process is green, pollution-free and very environment-friendly, the finally obtained lithium hydroxide solution contains low sodium and potassium impurities and is high in purity, and the byproduct sulf