Eisenstein's idea of depth composition has long been unnoticed in domestic academic circles.This essay introduces Eisenstein's class recordings and related theoretical articles in the 1930s to sort out his practical and theoretical exploration of depth composition,analyses two kinds of depth-of-field aesthetics of Eisenstein and Bazan from different perspectives,clarifies their theoretical confrontation in terms of the two concepts of reality under the concepts of Symbolism and Realism.Eisenstein's self-periodization highlights the unique theoretical significance of his 1933 teachings.The parallel development of the Building of Film Theory project and the Spherical Book outlines the three-stage evolution of montage-image-method,demonstrating Eisenstein's aesthetics of the image,which sees the inner reality as its essence.