In this study, the evergreen plant Cryptomeria japonica (L.f.) D.Don, 1839 forest gap in the subtropical region of China were taken as the research object. The effects of different forest gap ages (20 years) on soil physical properties and stoichiometric characteristics were analyzed in Lushan Mountain, China. With the increase of forest gap ages, the physical properties of soil surface layer in forest gap were improved, and the water holding capacity of soil was enhanced. The capillary porosity and total porosity of soil increased significantly, and the soil bulk density of 10–20 cm soil layer decreased. The increase of forest gap recovery years is beneficial to the increase of large particle size soil aggregates, and the increase of large particle size aggregates has a good effect on improving soil structure. The contents of carbon (C), nitrogen (N), and phosphorus (P) in soil showed an overall increasing trend with the increase of forest gap age and were significantly higher than those of Cryptomeria japonica pure forest (p < 0.05). The nutrient content of forest gap in 10–20 years was the highest, and the nutrient content of 0–10 cm soil layer was generally higher than that of 0–20 cm soil layer. The C:P and N:P in the soil showed an overall decreasing trend, while C:N was significantly smaller than other age gaps in 10–20 years. The results showed that soil physical properties and stoichiometric characteristics were improved with the increase of forest gap ages.