Abstract: Plant fibers are abundant and widely available in nature, possessing impressive features such as low density, high specific strength, and biodegradability. These properties make plant fibers a significant advantage in the development of sustainable insulation materials and a raw material candidate for novel sustainable foam composites. Plant fiber foams, due to their environmental friendliness and biodegradability, have gained considerable attention and are expected to partly replace non-biodegradable petroleum-based plastic foams, thereby alleviating plastic pollution. However, the development of plant fiber foams is still in its early stages, facing challenges such as complex manufacturing processes, long production cycles, and high production costs and thus limiting their large-scale production and widespread application. This review article systematically summarizes the current manufacturing technologies and processes for plant fiber foams, delves into the critical factors influencing the structure and performance of these foams, and provide an overview of their current application status. In addition, this review highlights the issues faced by plant fiber foams and outlines their future development directions, aiming to provide a valuable references and scientific basis for the optimization and development of high-performance plant fiber foams.