A kind of epoxy resin with high performance for space vehicle was prepared by using epoxy-terminated siloxane oligomer.Heat resistance,mechanical properties,atomic oxygen radiation resistance and ultraviolet aging resistance of the cured modified epoxy resin were systematically analyzed.The results showed that heat resistance,mechanical properties,atomic oxygen irradiation resistance and ultraviolet aging resistance of the cured epoxy resin modified by the epoxy-terminated siloxane oligomer were improved.Compared with the cured original epoxy resin,when the content of epoxy-terminated siloxane oligomer was 20%,the thermal weight loss temperature of 5%was 32℃higher than that of the cured original epoxy resin.10%thermogravimetric temperature is 57°C higher than that of cured original epoxy resin.The bending strength and impact strength increased from 100.0 MPa and 12.7 kJ/m^(2)to 114.4 MPa and 15.2 kJ/m^(2) respectively.After 36 hours of atomic oxygen irradiation,the mass loss of the cured resin is 21.25 g/cm^(2),which is 10.9%of that of the unmodified epoxy resin.At the same time,the anti-UV aging property of epoxy resin was improved.