Provided is an intelligent 3D printing method for a large 3D deep complex engineering geological model, including the steps of firstly, determining physical and mechanical parameters of the similar materials of the intact rock mass and the rock mass structure, and selecting a cementing agent; performing a small-scale 3D printing test at different material ratios and 3D printing parameters; determining the 3D printing similar material ratios and the 3D printing parameters; establishing a 3D digital model, planning printing paths, and determining pore diameters, number and combination form of the print heads; conveying the similar materials to the print heads; under the control of a 3D printing intelligent coupling control system, running each print head according to the planned and generated printing paths to complete printing; and finally, testing a printing effect of the model.