Preparation method of injection-grade L-lysine anhydrous crystal form

The invention provides a preparation method of an injection-grade L-lysine anhydrous crystal form, which comprises the following steps: 1) dissolving L-lysine hydrochloride with purified water to obtain a dissolved solution; 2) adsorbing the obtained dissolved solution through cation exchange resin, washing impurities, and eluting to obtain an eluent; 3) concentrating the obtained eluent under reduced pressure to obtain a concentrated solution; 4) transferring the concentrated solution to a crystallizing tank, firstly replacing air in the crystallizing tank with inert gas for multiple times, and then adding a water-soluble organic solvent in a stirring state for crystallization to obtain a crystallization solution; 5) filtering and drying to obtain an L-lysine anhydrous crystal form product.The purity of the product finally obtained through the method is larger than or equal to 99.5%, the quality meets the injection grade requirement, the anhydrous crystal form is stable, and the method is suitable for indust