Abstract: A flexible curing agent containing a long methylene chain segment was synthesized by bis-functional epoxy resin modifying aliphatic amine. The structure of product was characterized by infrared spectroscopy. The epoxy resin E-44 cured with the flexible curing agent was researched. By analysis of the relationship between mechanical strength and temperature, the optimum curing condition was obtained preliminarily, which was 80 ℃, 6 h. The heat resistances of the cured products at different proportion were characterized by thermogravimetric analysis (TGA), and the dynamic parameters, reactivity, best curing temperature and time were studied by differential scanning calorimetry (DSC), the results verify the correctness of the previous work. At last, the tensile shear strength was studied, and the results show that the tensile shear strengths at -196 ℃ , room temperature and 60 ℃ are 16.84, 14.73 and 13.52 MPa respectively when the curing proportion is 1:0.5, which fully meets the practical requirements.