This study used field sampling and laboratory tests to determine plant diversity and soil physical and chemical characteristics and their correlation in regeneration slash of Pinus sylvestris on Horqin sandy land. The results showed that after vegetation reconstruction in the regeneration slash of P. sylvestris, herbaceous species diversity changed dramatically and the number of species in the forest increased. Compared with the logged area of P. sylvestris, the soil physical and chemical characteristics were all improved after vegetation reconstruction. In areas with Populus xiaozhuanica and Acer mono, soil bulk density decreased and field capacity, organic matter, total nitrogen, and available potassium increased. In addition, total potassium in areas with Hemiptelea davidii and available phosphorus in areas with Prunus sibirica were substantially improved, and all variables were better in the upper than in the lower layer. There were significant differences in soil physical and chemical properties between different vegetation restoration types. With the increase in herbaceous species diversity, soil physical and chemical properties improved and herbaceous plant diversity and soil bulk density, field capacity, organic matter, and total phosphorus were significantly correlated. The results showed that soil physical and chemical properties and the recovery of herbaceous plant diversity interacted to promote the positive succession of the ecosystem. Based on these results, we elaborated on the changes in plant diversity and soil physical and chemical properties during the process of vegetation reconstruction in sandy land. The results have theoretical significance, and will provide practical guidance in the restoration and reconstruction of ecological systems in Horqin Sandy lands.