We study macroscopic magnon–phonon quantum entanglement in a magnomechanical system with Duffing nonlinearity and nonreciprocity induced by Barnett effect. When two degenerate phonon modes are coupled to a magnon mode supported by the yttrium iron garnet (YIG) sphere, the darkmode effect suppresses quantum entanglement under strong thermal noise. By introducing Duffing nonlinearity, the dark mode breaking (DMB) occurs, enabling noise-tolerant magnon–phonon entanglement through simultaneous ground-state cooling of the phonon modes. When the YIG sphere is spinning, the Barnett effect can induce nonreciprocal cooling effect in the DMB regime, resulting in one-way protection of the magnon-phonon quantum entanglement against thermal noise. Noise-tolerant nonreciprocal macroscopic quantum entanglement of magnon-phonon is realized. We further extend the scheme to a multimode magnomechanical system with many-body degenerate mechanical phonon modes, where magnon–phonon quantum entanglement network can be generated under strong thermal noise since multiple phonon modes can be cooled simultaneously to ground states in the DMB regime. Incorporating the Barnett effect, nonreciprocal simultaneous ground-state cooling of multiple phonon modes is achieved, which causes noise-tolerant magnon–phonon quantum entanglement network to exhibit strong nonreciprocity. Our results provide a promising route toward to control macroscopic quantum state, engineer many-body ground-state cooling, and construct chiral quantum network.