The present invention provides a blood circulation demonstrator for teaching. A simulated transparent heart used for teaching is divided into left and right ventricles. The two ventricles are separated into a left lower ventricle, a right lower ventricle, a left upper atrium and a right upper atrium by partitions with middle transverse check valve ports. A transparent lower circulation outlet tubehead with a submersible pump arranged in the left lower ventricle encircles the lower part and is provided with a transparent lower circulation return tube head to enter the right upper atrium through an integrated transparent lower circulation tube. A transparent upper circulation outlet tube head arranged in the right lower ventricle encircles the upper part through an integrated transparent upper circulation tube and is provided with a transparent upper circulation return tube head to enter the left upper atrium. When the demonstrator is used for teaching, red liquid water is put in the heart, that is to say, the red liquid water circulates and flows in the circulation tube through the operation of the submersible pump, so the simulation of blood circulation states can be observed clearly.