Abstract: Polybenzoxazine resins have many excellent properties. However, most of the raw materials for the synthesis of benzoxazines are derived from petroleum resources. With the global energy crisis and current environmental problems, polybenzoxazines are facing challenges in terms of supply and cost. Therefore, the search of green raw materials for synthesizing fully-bio-based benzoxazine is a sustainable development and is also of great significance for developing benzoxazine science. In this paper, magnolol was used with furfurylamine and dehydroabietylamine by a simple solvent method to prepare two fully-bio-based benzoxazines: M-fa and M-da, respectively. The structures of the two monomers were confirmed by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance analysis (¹H-NMR and ¹³C-NMR) and ESI-high resolution time-of-flight mass spectrometer (ESI-MS). Differential scanning calorimetry (DSC) were performed to monitor the curing behaviors of M-fa and M-da, and the exothermic peaks were displayed in the spectra of the oxazine ring and the double bond. The thermal stability of the corresponding polybenzoxazines was supported by thermogravimetric analysis (TGA). The char yield of P(M-fa) and P(M-da) at 800 ℃ reached 69% and 41%, respectively. The limiting oxygen indexes (LOI) of the polybenzoxazine resins were higher than 30, suggesting a good flame retardancy. The use of polybenzoxazine for the corrosion protection of Q235 low-carbon steel was also studied. The results of open circuit voltage (OCP) curves and Tafel plots demonstrate that the polymer coatings provide good corrosion resistance. This study enriches the diversity of benzoxazine resins and is conductive to environmental protection and sustainable development.