The invention relates to a method for alkylating amine and amino acid, and provides a method for alkylating amine and amino acid, which has high efficiency and chemical selectivity, and is mild and environment-friendly. The method comprises the following steps of: adding amine or amino acid, a catalyst and an alkylating reagent in a reaction flask, pumping air in the system, and introducing hydrogen to enable the whole system to be in a hydrogen atmosphere; after reaction, filtering to remove the catalyst, washing the filter cake, and decompressing and condensing the filtrate to obtain the product, wherein the catalyst is Pd/C or Pd(OH)2/C, and the alkylating reagent is alcohol. The alcohol is directly used as a substrate, and can be conveniently and easily obtained compared with halogenated hydrocarbon. In the reaction, dehydration and condensation are directly carried out to alkylate the amine, thereby halogeno salt generated by using the halogenated hydrocarbon is avoided, in addition, water is the unique side product, thereby the method is environment friendly. Documents report that in the traditional methods, the reaction condition is rigorous, and most methods are carried out under high temperature, but the method provided by the invention has mild reaction condition, and the reaction can be directly carried out under room temperature. The catalyst can be recycled, thereby the invention has very good industrial application prospect.