This standard specifies a method for the determination of lithium hydroxide content in lithium hydroxide monohydrate by acid-base Titrimetric method. It is suitable for samples of lithium hydroxide monohydrate with a mass fraction greater than or equal to 55.00%. First dissolve the sample in muriatic acid standard solution, then use methyl red-bromocresol green as an indicator, and titrate the sample with muriatic acid standard solution to calculate the lithium hydroxide content. At the same time, the sodium, potassium and carbonic acid root content in the sample need to be converted into lithium hydroxide content and deducted from the total fruit.