To find the effect of planting density on peanut yield and dry matter accumulation with single-seed precision sowing mode,‘Tieyinghua 1’and‘TangA825’were used as research materials. 6 planting densities of 7.5×104, 15×104, 22.5×104, 30×104, 37.5×104 and 18×104 plants/hm2 were set up. The results showed that proper increase of planting density under single-seed precision sowing was good for peanut production. The large-seed type‘Tieyinghua 1’had the best yield at 15×104 plants/hm2, 15.8% more than that of the control. The medium and small-seed type‘TangA825’had the best yield at 22.5×104 plants/hm2, 26.5% more than that of the control. Planting density did not have obvious influence on the dry matter accumulation at the earlier stage, and at the later stage, the group yields, the maximum stage accumulation, the maximum daily accumulation, the dry matter accumulation of leaves, stems and stalks had a peak change with the increase of planting density, while the dry matter accumulation, output rate, contribution rate of single plant decreased significantly with the increase of planting density.