Abstract <p>The evolving application fields put forward higher requirements on the flame retardant properties of bamboo fiber composites. However, the addition of flame retardants inevitably affects the physical and mechanical properties of bamboo fiber composites, primarily due to the agglomeration of fibers, which leads to the uneven distribution of flame retardants and subsequently results in material defects. To improve the uniformity of impregnation, this work investigated the impact of different impregnation methods on the morphology, void characteristics, mechanical properties, heat resistance, and combustion properties of hot-press-molded bamboo fiber/phenolic resin composites, and analyzed the influence mechanism. The results showed that the vacuum pressurized impregnation method could effectively improve the impregnation degree and void structure of the bamboo fiber composites, thus obtaining excellent water resistance (water absorption = 1.95%), mechanical strength (flexural strength = 69.88&#xa0;MPa, impact strength = 15.17&#xa0;KJ m⁻²) and flame retardant properties (UL-94&#xa0;V-0). Comparison with the existing market standards TL 52448-98 and GB 8410-06 indicated that the prepared bamboo fiber composites meet the application requirements of automotive interior materials. This work provides an economical and effective method for manufacturing bamboo fiber composites for automotive interior parts with balanced physical, mechanical, and flame retardant properties.</p> Graphical abstract <p></p>