The N, N-dimethyltrimethylsilylamine (DMATMS) was synthesized by reacting trimethylchlorosilane （TMCS） with dimethylamine catalyzed by timethylmethoxysilane in the solvent 1, 2, 4-trimethylbenzene（TMB）. Effects of molar ratio of TMCS to TMB，reaction temperature, amount of catalyst, reaction time on the yield of DMATMS were investigated, and the target compound was characterized by means of FTIR, 1H NMR and GC. The results indicated that the highest yield of DMATMS was 90.77% when the molar ratio of TMCS to TMB was 1: 2, the reaction temperature was 30 ℃, amount of catalyst is 0.3 mL, feeding time of TMCS is 20 min, and reaction time was 60 min. After purification, the purity of DMATMS reaches 97.31%.