A method of fabricating a plant fiber reinforced biomass resin based foam laminate comprising a reinforcement body of ramie, flax, hemp or jute plant fiber, carried with an expandable biomass resin and a biomass epoxy resin to form the composite material foam laminate, wherein the reinforcement body has a weight content of 40% to 60% comprising: preparing a fiber felt with a thickness of 0.1-5 mm from a natural fiber of a plant selected from ramie, flax, hemp or jute by an available plant fiber felting technology in industry, and performing a fire retardation and a compatibility promotion treatment to the plant fiber felt; preparing a micro-capsule foaming agent using polylactic acid as a capsule shell filled with alkane therein, the micro-capsule foaming agent having a particle size of 5 μm-50 μm, the alkane has an amount enabling the micro-capsule to expand by 50-100 times in term of volume after being heated up to 100 °C -180 °C; preparing a Maleated rosin based epoxy resin curing agent, mixing and grinding the Maleated rosin based epoxy resin curing agent with the epoxy resin to prepare a fine powder of a partial biomass epoxy resin, the fine powder having a particle size of 10 μm to 100 μm; adding the micro-capsule foaming agent in a content of 5%-15% to the fine powder of the epoxy resin to prepare an aqueous suspension; fully impregnating the plant fiber felt after the fire retardation and compatibility promotion treatment into the suspension and drying to obtain a foaming pre-impreg to be ready for use; and heating the dried plant fiber felt according to up to 100 °C -180 °C for 10 min-15 min, so as to expand the plant fiber felt by 5-8 times in a thickness thereof to obtain a continuous plant fiber reinforced biomass resin composite foam laminate. preparing a fiber felt with a thickness of 0.1-5 mm from a natural fiber of a plant selected from ramie, flax, hemp or jute by an available plant fiber felting technology in industry, and performing a fire retardation and a compatibility promotion treatment to the plant fiber felt; preparing a micro-capsule foaming agent using polylactic acid as a capsule shell filled with alkane therein, the micro-capsule foaming agent having a particle size of 5 μm-50 μm, the alkane has an amount enabling the micro-capsule to expand by 50-100 times in term of volume after being heated up to 100 °C -180 °C; preparing a Maleated rosin based epoxy resin curing agent, mixing and grinding the Maleated rosin based epoxy resin curing agent with the epoxy resin to prepare a fine powder of a partial biomass epoxy resin, the fine powder having a particle size of 10 μm to 100 μm; adding the micro-capsule foaming agent in a content of 5%-15% to the fine powder of the epoxy resin to prepare an aqueous suspension; fully impregnating the plant fiber felt after the fire retardation and compatibility promotion treatment into the suspension and drying to obtain a foaming pre-impreg to be ready for use; and heating the dried plant fiber felt according to up to 100 °C -180 °C for 10 min-15 min, so as to expand the plant fiber felt by 5-8 times in a thickness thereof to obtain a continuous plant fiber reinforced biomass resin composite foam laminate.