Abstract: The present disclosure provides an activated carbon-based all-carbon membrane (ACM), which is formed by using activated carbon as a base material and graphene as a crosslinking agent for connection, and can stably exist independent of a substrate. The membrane surface pore structure can be adjusted by the addition proportion of graphene, and the membrane surface pore size can be adjusted from micron-scale to nano-scale. The preparation method of ACM comprises uniformly mixing and then filtering an activated carbon dispersion and a graphene dispersion, then the graphene and the activated carbon are assembled on the membrane filter substrate. The membrane can be used in the fields such as water and air purification, chemical catalysis, and energy reservation.