Soil fertility is a reflection of the basic properties and essential features of the soil, and fertile soils can provide indispensable nutrients for plant growth. Soil nutrients are one of the most important parameters for the evaluation of soil fertility. Spatial orientation and distribution of soil nutrients directly affect the level of soil fertility and ecological restoration. Magnolia officinalis is a traditional medicinal tree species in China, and it is often used as the preferred tree on Qin-Ba Mountain. In order to clarify the distribution of soil nutrients and soil fertility status of different Magnolia officinalis communities on Qin-Ba Mountain, five communities were analyzed: 2-year-old, 4-year-old, 7-year-old, and 11-year-old Magnolia officinalis and 7-year-old Magnolia officinalis officinalis. Two other plant communities were also selected: Eucommia ulmoides-Magnolia officinalis and Macrocarpium officinale-Magnolia officinalis. The soil nutrients of the seven communities were determined using one-way analysis of variance, and the soil integrated fertility index of the seven communities was evaluated using the improved analytic hierarchy process. The results showed that the soil nutrients of the seven communities in the same soil layers were significantly different (P < 0.05). In addition, the parameters in different soil layers also differed remarkably. Soil organic matter, total N, available N, available P, and available K in the seven communities decreased with soil depth in the profile distribution; however, total P and total K did not show any specific characteristics. A comprehensive evaluation showed that the soil integrated fertility index of 4-year-old Magnolia officinalis was the highest (1.054) among the seven communities, while that of 11-year-old Magnolia officinalis was the lowest (-0.840). With the growth of plantations, soil fertility of Magnolia officinalis communities has declined. Soil fertility of Macrocarpium officinale-Magnolia officinalis (0.673) was higher than that of 7-year-old Magnolia officinalis, whereas the soil fertility of Eucommia ulmoides-Magnolia officinalis (-0.812) was lower than that of 4-year-old Magnolia officinalis. Therefore, Macrocarpium officinale-Magnolia officinalis could improve soil fertility on Qin-Ba Mountain.