The cyanate ester resins were prepared by adding different low content epoxy AG80 and benzyl dimethylamine （BDMA）. The microstructure， curing heat effect， vacuum outgassing properties， mechanical properties， water absorption and thermal weight loss of low content epoxy modified cyanate ester resin were analyzed. The experimental results show that AG80 epoxy resin with mass fraction of 5% and 8% can effectively promote the curing degree of cyanate ester， reduce the number of uncured small molecules， and improve the vacuum outgassing properties of cyanate ester resin under the action of catalyst BDMA. BADCy-1 has the best vacuum outgassing properties and moisture resistance， in which the total mass loss （TML） and collected volatile condensable material （CVCM） are 0.41% and 0.03%， respectively， and the water absorption is reduced by 15%. The mechanical properties of BADCy-2 are optimized， and the tensile strength and flexural strength are improved by 23% and 20%， respectively. At the same time， the heat resistance of the material decreases with the increase of epoxy resin content.