The invention relates to a foundry sand charging device used in the process of resin bonded sand foundry molding, which has the structure that the outlet end of a quick catalyst liquid material barrel is connected with a quick catalyst feeding electromagnetic valve; the outlet end of the quick catalyst feeding electromagnetic valve is connected with a weighing and baiting system; the outlet end of a slow catalyst liquid material barrel is connected with a slow catalyst feeding electromagnetic valve; the outlet end of the slow catalyst feeding electromagnetic valve is connected with the weighing and baiting system; the outlet end of a weighing and mixing barrel is connected with the feed end of a liquid material valve; the discharge end of the liquid material valve is connected with the feed end of a buffering barrel; the discharge end of the buffering barrel is connected with the feed end of a filter; the discharge end of the filter is connected with the feed end of a liquid material pump; the discharge end of the liquid material pump is connected with the feed end of a flowmeter; and the discharge end of the flowmeter is connected with the feed end of a three-way valve. The invention can automatically feed and intelligently proportion the liquid material A and the liquid material B, and enable the effective flow range of the pump to be as wide as possible on the premise that the precision of the pump is ensured.