Biomass is a low-cost, readily available, widely distributed, environmentally friendly and renewable carbon source. How to realize the reasonable disposal of biomass is an important question because it is a by-product/bio-waste of agriculture, industry and forestry. Carbon nanomaterials (CNMs), especially carbon nanotubes (CNTs), carbon nanofibers (CNFs), and graphene, conventionally prepared from fossil fuels are the most in-demand carbon materials at present due to their outstanding characteristics and extensive applications. The purpose of this review is to overview the progress in the technology of the preparation of CNMs from biomass in the last few decades. The production of these high value-added CNMs from biomass is intensively investigated, together with the applications of biomass as catalysts and catalyst supports during the preparation of CNMs. Finally, the advances in the application of biomass-based CNMs in terms of ecological remediation, photocatalysis, electrode materials for supercapacitors and batteries, chemical catalysis and composites are briefly summarized to develop the potential market of biomass-based CNMs.