The invention relates to the field of composite materials, and particularly relates to a bamboo fiber polylactic acid composite material. The composite material is prepared from the following raw materials: absolute ethyl alcohol, silane coupler, epoxy resin, bamboo fibers, starch, formamide, dicyandiamide, ammonium polyphosphate and acetyl tributyl citrate. According to the composite material, the interface acting force between polylactic acid and natural plant fibers is weakened due to the surfactant, and the biological compatibility of polylatic acid is effectively improved; and the composite material prepared by adding a flame retardant with a remarkable flame retardant efficiency has a remarkable flame retardant efficiency and relatively high limit oxygen index. The flame retardant effect of the polylactic acid composite material is not influenced by decomposition of polylactic acid, and still has excellent flame retardant efficiency in the degrading cycle of the polylactic acid material.