The invention belongs to the field of papermaking and particularly relates to a low-carbon papermaking method which aims to solve the problems about raw materials, environments and energy sources in the development of papermaking industries in China. The low-carbon papermaking method specifically comprises the following steps of: in order to realize low-carbon papermaking, comprehensively taking crop straws as an energy source to produce secondary high-pressure steam to generate power and taking the crop straws as raw materials to make paper pulp and separate the paper pulp, pollutant black liquid and bleaching effluent; and making various paper through the paper pulp, preparing sodium ligninsulfonate from the pollutant black liquid, and preparing anhydrous calcium chloride from chlorine-containing bleaching sewage. The low-carbon papermaking method disclosed by the invention has the advantages of realizing low-carbon papermaking ecological industry, circular economy, and CP (cleaner production) zero emission by virtue of the comprehensive utilization of the straws, and solves the problems about the raw materials, the environment and the energy sources in the development of the papermaking industries.