The invention relates to the technical field of chemical materials, in particular to non-toxic long-acting solvent-free drinking water cabin paint and a preparation method thereof. The non-toxic long-acting solvent-free drinking water cabin paint comprises a component A and a component B, wherein the component A comprises epoxy resin, dimer acid modified epoxy resin, an amino silane coupling agent, a dispersing agent, a defoaming agent, non-toxic filler, glass flakes, a nanometer double-layer material and a thixotropic agent; the component B comprises an amine curing agent and an epoxy silanecoupling agent. Compared with the prior art, the non-toxic long-acting solvent-free drinking water cabin paint prepared through the preparation method is lower in VOC, and the VOC is lower than 50 g/L; the mixing viscosity is moderate, the salt fog resistance is excellent, and the salt fog resistance reaches 5000 h when the thickness of a dry film is 250 micron. Besides, the adhesive force is notlower than 11 MPa; through a sanitary performance test, long-acting anti-corrosion protection requirements of a drinking water cabin, drinking water conveying and distributing water pipelines and theinner wall of equipment are met.