The paper introduced epoxy resin modified by active nanometre CaCO_3 based on one-component resin, and to test the properties and study epoxy resin/CaCO_3 nanometre composite by changing the additive amount of nanometre Ca CO_3. The result showed: mechanical property, adhesive property and thermal property of the composite were changed by addition nanometre CaCO_3. While the additive amount was 20%, the synthetical properties of the composite reached the best point. So the active nanometre CaCO_3 could replace the expensive silica to reinforce the materials and reduce the cost.