The invention belongs to the field of lithium-sulfur batteries, and particularly relates to a preparation method of a sulfur-containing electrode material. The method includes the three main steps of preprocessing of a porous matrix, filling of sulfur-containing components and preparation of the sulfur-containing electrode material. At the porous matrix preprocessing stage, gas components in the hole structure of the porous matrix are sufficiently discharged through long-time and high-vacuum processing, and enough space is preserved for filling of sulfur-containing components. In the mixing process of the sulfur-containing components and the porous matrix and before filling of the sulfur-containing components, the high vacuum degree is kept all the time, reserved space in the hole structure of the porous matrix can be kept, and the porous structure can be filled with enough sulfur-containing components.