N，N，N，N，N′-Pentakis （2-hydroxyethyl）-1，4，7-triazaheptane was synthesized by diethylenetriamine and 2-chloroethanol as the main raw materials. Single-factor experiments and orthogonal experiments were used to optimize the ratio of raw materials and process conditions. The optimum molar ratio of diethylenetriamine and 2-chloroethanol was 1: 6.5，and the optimum process conditions were as follows: reaction temperature was 85 ℃ and reaction time was 5 h. Under the optimal reaction conditions，the yields can reach 98.76 %. The structure of final product was characterized by determining hydroxyl value and amine value，FT-IR，1H-NMR and ES-MS.