Abstract: Abstract: Bamboo flour and polylactic acid as raw materials preparation of bamboo flour/polylactic acid composites, flame retardant and smoke suppression properties of bamboo flour/polylactic acid composites were tested after treated with Aluminium Hydroxide (ATH) and Ammonium Polyphosphate (APP). The results show that two flame retardants both added char rate about 2 times of composites at high temperature, respectively has achieved 24.7% and 25.6%. ATH and APP both effectively enhanced flame retardant properties of composites. And APP is more obvious in inhibited heat release of composites in combustion process, but large amount of smoke. The effect of ATH on the inhibition heat release of composites is less than APP, but smoke suppression effect is obvious.