The invention discloses a method for preparing a paper-based material through coniferous and broad-leaved mixed sodium hydroxide anthraquinone totally-chlorine-free bleaching chemical pulp. The method comprises the following steps that (1) coniferous and broad-leaved mixed pulp obtained in a stewing mode according to a sulfate digestion process is used as a paper pulp raw material and divided into three parts for pulping, wherein the pulping degree of the first part of paper pulp is 10-20 SR, the pulping degree of the second part of paper pulp is 45-50 SR, and the pulping degree of the third part of paper pulp is 55-65 SR; (2) the three parts of paper pulp prepared in the step (1) are mixed at a certain proportion, and a pulp mixture is obtained, wherein the mass ratio of the first part of paper pulp to the second part of paper pulp to the third part of paper pulp is 10-20:60-85:5-10; and (3) the pulp mixture obtained in the step (2) is copied or pressed, and accordingly the paper-based material is obtained.