Epoxy resin composition capable of foaming at room temperature and preparation method thereof

The invention relates to an epoxy resin composition capable of foaming and curing at room temperature or curing below 60 DEG C and a preparation method thereof. The A component of the composition comprises epoxy resin, a modifier, pigments and fillers, the B component is a curing agent, and the C component comprises a foaming agent and a foam evening agent. The curing agent is aliphatic amine which is one or more than one compound(s) in a modified aliphatic amine curing agent, and the foaming agent is silicone oil. The proportion by weight of the three components is 100: 10-40: 1-5. The foaming temperature of the composition is 10-35 DEG C, and the curing process needs 2-7 days at the room temperature or 2 hours at 60 DEG C or 12-16 hours at the room temperature and 1-3 hours at 60 DEG C. The composition has good compression strength, impact strength and other mechanical properties, as well as good breakdown voltage strength and other electrical insulation performances after curing, and can be casted in situ,