The work aims to prepare a high-performance poplar powder/poly (β-hydroxybutyrate valerate) (PHBV) composite cushion material that can be used in transport packaging field as the cushion packaging material. With maleic anhydride grafted polypropylene (MAPP) as the coupling agent and NaHCO3 and AC as the foaming agent, blending hot pressing process was adopted to prepare the poplar powder/PHBV composite material. Then, mechanical properties and cushioning performance were tested and performance characterization was carried out by scanning electron microscope (SEM), Fourier infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) to analyze the effects of different wood-plastic ratios, types and amount of foaming agent on the micro-interface and cushioning performance of poplar/PHBV composite material. According to the results, the cushioning performance, energy absorption and thermal performance of composite material were the best when the wood/plastic ratio was 6:4. When NaHCO3 and AC were added in 2.0 g and 1.5 g respectively, the cells were numerous and uniform, and were interwoven and connected with wood fibers to form a stable and continuous cell structure. There were no stress concentration points under compression, and energy absorption increased by 34.6% and 33.8% respectively. The enthalpy of fusion was increased by 43.74 % and 41.83 % when an appropriate amount of foaming agent was added, and the crystallization rate with AC foaming materials was significantly increased. When the mass ratio of poplar powder to PHBV is 6 :4, and the mass of NaHCO3 foaming agent and AC foaming agent is 2.0 g and 1.5 g, respectively, the prepared poplar powder/PHBV composite material has excellent cushioning performance and has potential application prospects in the field of transport packaging.