Preparation method of ibuprofen L-lysine salt

The invention provides a preparation method of an ibuprofen L-lysine salt, which comprises the following steps: 1) feeding ibuprofen and L-lysine as raw materials, heating and dissolving the raw materials in a low alcohol or a water-containing low alcohol solution, filtering while the solution is hot, and concentrating the filtrate to obtain a thick liquid containing the ibuprofen L-lysine salt; 2) adding pure water into the thick liquid containing the ibuprofen L-lysine salt for dissolving, then adding a low-polarity solvent for reflux azeotropic water separation, and separating residual alcohol and water to obtain a dispersed solid; and 3) cooling and filtering the dispersed solid, and drying under reduced pressure to obtain the particle-dispersed ibuprofen L-lysine salt. According to the method, the low-polarity solvent is adopted to carry out reflux azeotropic water separation on the ibuprofen L-lysine salt liquid, and the advantages that the ibuprofen L-lysine salt is poor in solubility in the low-polari