Limestone dust powder is the solid waste produced during the mining of stone aggregate. Using it with high value has the dual values for the environment and economy. In this paper, limestone dust powder was used to replace calcium carbonate to prepare polyvinyl chloride (PVC) stone-plastic composites. The composition of limestone dust powder was analyzed by XRD and X-ray fluorescence spectroscopy. The effects of particle size, content and surface treatment agents of limestone dust powder on the morphology and mechanical properties of limestone dust powder/PVC composites were studied. The results show that the main component of limestone dust is calcium carbonate, and after stearic acid treatment, the dust can disperse well and has better interface interaction with PVC, thus improving the mechanical properties of limestone dust powder/PVC composites. The mechanical properties of limestone dust powder/PVC composites decrease with the increase of particle size and content. Under the same amount of stone powder, the tensile strength and hardness of limestone dust powder/PVC composites are slightly higher than those of calcium carbonate/PVC. The limestone dust powder/PVC stone-plastic floor material is prepared through pilot production, and the performance meets the corresponding national standards.