Abstract: This study aimed to explore the short-term effects of different thinning intensities on soil physical properties and tree growth in Pinus armandi plantation, providing a theoretical basis for the scientific management of P. armandi plantation. The research was conducted in P. armandi plantation in Huidong County, Liangshan Prefecture, Sichuan Province. Three thinning treatments were set up: light thinning (1800 trees/ha), moderate thinning (1350 trees/ha), and heavy thinning (900 trees/ha), with an unthinned control group for comparison. Through three years of experimental treatment, soil physical properties and tree growth indicators were investigated and analyzed. The results showed that: (1) Thinning promoted the growth of P. armandii plantation. After three years of thinning, both diameter at breast height and tree height significantly higher than those of the control (P < 0.05), but there was no significant difference between different thinning intensities. (2) Thinning significantly improved soil and water conservation. After thinning, soil bulk density decreased, while the total porosity, capillary porosity, and water holding capacity increased, and the effect of heavy thinning was the most significant (P < 0.05). The study indicates that thinning can effectively promote tree growth, improve the soil structure and enhace the soil water conservation capacity, and the effect of heavy thinning (900 trees/ha) is the most obvious.