The invention relates to a composition capable of being molten and processed and a preparation method thereof. The composition contains fine particle padding, low-density polyethylene, linear low-density polyethylene, dispersant and fluoropolymer, wherein the dispersant is macromolecule dispersant or high polymer dispersant, and is formed by one or the combination of saponated oligomerization dispersant, polyester dispersant containing substituted amine end groups, and polycarboxylates dispersant. The preparation method of the composition comprises the following steps: a, dehydrating the fine particle padding at more than 140 DEG C; b, modifying the surface of the fine particle padding by using the macromolecule dispersant or high polymer dispersant; c, uniformly mixing the fine particle padding, the low-density polyethylene and the linear low-density polyethylene; d, feeding mixture obtained by the step c into a screw extruder; e, adding fluoropolymer processing agent into a measurement section of the screw extruder; f, screw-extruding; and g, cutting. The molten and processed composition can be extruded and pulled into a ventilated membrane, and is applied to disposable diaper, feminine hygiene / panty liner and the like.