Biomass is one of the most promising clean energy sources. The porous carbon materials prepared by biomass as electrode materials of electric double-layer capacitors (EDLCs) are easily available at a low price, which would greatly reduce the cost of the production. However, carbon materials made with biomass generally have many disadvantages such as low specific surface area (SSA), poor pore size structure, and difficulty to control the pore diameter, which results in the poor EDLC performance. In this paper, the prime purpose is to expose the recent progress of biomass carbon in the fields of electrode materials of EDLC. The review provides a comprehensive literature review that is focused on EDLC electrodes derived from biochar of the evidence of 181 publications published over a period of 30 years from 1989 to 2019. Various carbon materials derived from different biomass for electrode of EDLC are discussed. The most promising methods for the preparation of several biomass carbons are described in detail. Some factors such as SSA, pore size structure, surface functional groups, and electrolyte are further analyzed to discuss the effects on the electrochemical performance of the EDLC. Notably, current deficiencies and possible solutions of preparation methods of biomass carbon as electrode materials are outlined. And the future research trends in this field are prospected.