Forest fire is one of the important disturbances in the forest ecosystem of subtropical China. Through its impact on soil physicochemical properties, forest fire can impact on the species composition and population dynamics of post-fire plant and microbial communities. However, there are few studies on forest fire severity and lack of corresponding theoretical mechanisms in subtropical China. Here, we combined forest fire severity (unburned, low-severity forest fires, moderate-severity forest fires and high-severity forest fires), post-fire recovery time (one month after the forest fire, six months after the forest fire and one year after the forest fire), and soil depth (0-10 cm and 10-20 cm). The analysis methods used one-way analyses of variance (ANOVA), multivariate analyses of variance (MANOVA), Pearson's correlation analysis, LSD post-test, and principal component analysis (PCA). Here we studied the impact of forest fires of different severities on the spatiotemporal dynamics of soil physical and chemical properties (soil temperature, soil humidity, soil moisture content, soil bulk density, soil total porosity, soil pH, soil organic carbon, soil total nitrogen, soil available nitrogen, soil total phosphorus and soil available phosphorus) of a Masson pine forest in Daye City, Hubei province. We aimed to provide a scientific theoretical basis for the post-fire forest restoration and management of the Masson pine forest in subtropical China. The results show that: (1) The impact of forest fire on soil physical and chemical properties was positively correlated to the severity of forest fire and negatively correlated to the recovery time and soil depth. (2) With the increase of recovery time, the total soil porosity gradually increased, while soil bulk density, pH, available nitrogen, and available phosphorus gradually decreased; under low-severity fires, organic carbon and total nitrogen decreased gradually but increased gradually under the moderate-severity and high-severity fires. (3) With the increase of soil depth, the soil bulk density and porosity increased under four fire severities, and soil organic carbon and total nitrogen decreased. There was no significant difference in soil moisture content between the different soil depths. (4) Low-severity forest fires significantly increased the correlation between most soil physical and chemical properties, while moderate to high-severity forest fires led to a shift in the correlation between soil organic carbon, total nitrogen, and other soil physicochemical properties. In the subtropical Masson pine forest, soil physicochemical properties respond positively to low-severity forest fires, and negatively to high-severity forest fires. Low to moderate-severity forest fires can promote regeneration of understory vegetation and enhances ecosystem stability.