The core of HUANG Yuanyu's Four Sages'Heart Source is'four images of the earth pivot and flow around in one breath',which has many similarities with inner alchemy.Inner alchemy is a human life science with dual cultivation of life.HUANG Yuanyu cited'Wu Ji Tu'in inner alchemy as his theoretical basis,and applied the theory of Dan dao to medicine,with medicine as the carrier and medicine as the guide.In the following,the author mainly compares and expounds the theories of ancestral qi,Wu Ji Tu,spirit,qi circulation,four images,Kan Li,and so on,through the classic Dan book Life Gui Zhi and Four Sagess Heart Source,in order to explain some principles and scientificity for inner alchemy and find new treatment ideas and methods for traditional Chinese medicine.