The invention relates to a salting method of a 2-(1-amido-ethyl)-N-phenyl thiazole-4-methanamide compound and a derivative thereof, and application thereof in the aspects of prevention and treatment of limnetic algae. The 2-(1-amido-ethyl)-N-phenyl thiazole-4-methanamide compound is a compound shown in a structural general formula, wherein X is HCl, H2SO4, H3PO4, maleic acid, fumaric acid, para-toluenesulfonic acid, citric acid, oxalic acid, malic acid, acetic acid, tartaric acid and the like; R, R1, R2 and R3 are H, halogens, C2-C5 alkyls, sulfo groups, alkoxy, nitryl, amino, substituted amino and the like. The salifying method of the compound is simple and convenient in process, and applicable to industrial production, and has the potential of developing an efficient algicide. The 2-(1-amido-ethyl)-N-phenyl thiazole-4-methanamide compound has excellent broad-spectrum killing algae activity on limnetic algae chlorophyta verdigris microcystin algae, scenedesmus obliquus, chlorella pyrenoidosa and the like. Compared with the traditional algicide, the 2-(1-amido-ethyl)-N-phenyl thiazole-4-methanamide compound has the characteristics of being high in activity, friendly to environment, low in toxicity on non-target organisms and the like, simple in synthetic method, and is an algicide lead compound with value.