In this study, we developed a novel blow spinning technology to construct large-scale porous sponges composed by carbon microfibers with strong absorption of oil. The microfiber sponge had a weight expansion of 184 times after oil absorption. Considering the outstanding mechanical properties and good thermal stability of the 3D carbon sponge, the carbon microfiber sponge could be regenerated with various methods, such as squeezing, combustion and distillation. More importantly, the preparation process of carbon microfiber sponges is very environment-friendly and cost-effective. Therefore, it has great potential to be further used in industrial applications for water treatment.