The invention discloses a method for preparing a paper-based material from a biochemical technology ECF bleached sulfate pulp of fast-growing poplar. The method comprises the following steps: 1, preparing a paper pulp through a biochemical technology ECF bleaching technology of sulfate pulp of the fast-growing poplar; and 2, carrying out gradient beating on the prepared paper pulp to obtain paper pulp with three beating degrees, wherein the beating degree of first paper pulp is 10-30 DEG SR, the beating degree of second paper pulp is 30-55 DEG SR, and the beating degree of third paper pulp is 55-70 DEG SR; and 3, carrying out making molding or compaction molding on the mixed pulp to obtain the paper-based material. The method adopting a gradient beating technology and a self-adding technology solves the disadvantages of single beating technologies in the prior art, and avoids use of extra additives, and the produced paper-based material has the advantages of high folding strength, high bursting strength and high tearing resistance index, is suitable for producing various types of paper bases, and is especially for producing white cardboard raw paper-based materials.