Abstract: For preparing high-performance wood plastic composites and broading the application fields, the surface of bamboo flour was modified by A-171 silane coupling agent and an amount of bauxite was added into it. The bamboo flour/high density polyethylene (HDPE) composites were prepared by hot pressing technology. The influence of bauxite content on mechanical properties, heat resistance and tribological behavior of the bamboo flour/HDPE composites were investigated. The crystallization characteristics of bauxite were observed using XRD and their morphology of fracture surface and distribution of elements on the surface were analyzed by SEM and EDS. The results show that the mechanical strength, heat resistance and the wear resistance of bamboo flour/HDPE composites are improved by adding the appropriate content of bauxite. Bauxite can be evenly distributed in bamboo flour/HDPE composite matrix and bear the load effectively, and the crystallization properties of bamboo flour/HDPE composites are improved. The deformation and failure of bamboo flour/HDPE composites under exterior stress were reduced. However, when the content of bauxite is too high, the mechanical strength and the wear resistance decrease, and the coefficient of linear thermal expansion of bamboo flour/HDPE composites increases, because that the bauxite is unevenly distributed and formes agglomeration easily.