The invention belongs to the technical field of simulating compression resistance of a homogeneous rock model, and discloses a homogeneous rock model with uniaxial compressive strength of 20-30 MPa, and a preparation method. The homogeneous rock model comprises an upper-layer homogeneous rock model body, a molding layer, a lower-layer homogeneous rock model body and a cavern, wherein the upper-layer homogeneous rock model body and the lower-layer homogeneous rock model body are connected to form a homogeneous rock model body in a binding manner through the molding layer, and the cylindrical cavern is arranged in the center of the homogeneous rock model body. After absorbing free moisture, a molding material is naturally dried in the hardening process, free from roasting, and suitable for large-area binding. Furthermore, the through connection between broken cracks of an upper half model and a lower half model can be guaranteed by the crispy molding material and a model material which have identical physical properties, and the identical breaking shapes of the upper half model and the lower half model can be guaranteed.