The resin sand is a molding and core making technology which the mould and core sand will be self-harded in some time in the flask when added in certain amount glue. At present, the foundry usually applies furan resin sand, ester-hardening alkaline phenolic resin sand and pep-set resin sand. The great characteristic is that under the room temperature the resin sand can be self-harded. The self-harded rate and hardness is related to the room temperature, environment humidity. It fits the single piece, small batch, various medium and large scale casting’s mould and core, widely used in the tool, general, heavy, shipbuilding, locomotive, motorbike.