Forest restoration can effectively reduce soil erosion in mountainous areas. However, the soil water movement processes changed with trees growing older and extreme rainfall events occurring frequently. Studying the responses of soil moisture to rainfall in the planted forests with different ages is crucial for the mountainous vegetation construction and forest ecosystem water storage function improvement. In this study, typical artificial Platycladus orientalis forests with two ages (90 years old and 60 years old) in Chongling catchment in the upper reaches of Baiyangdian were selected to analyze the responses of soil water movement to different rainfall events. The soil water dynamics in the 0—100 cm layer were monitored during rainy season in 2021 (extreme wet year) and 2022 (normal year), respectively. The results showed that: (1) The total number of soil water response times to rainfall events decreased with the increase of soil depth in both forests. The maximum number of soil water response times occurred at 10 cm, and the number was 31 and 34 times in the 90-year and 60-year Platycladus orientalis forests, respectively. The time lags between the maximum soil water content and the peak rainfall intensity increased as the soil depth deepened. It reached the maximum at 100 cm, which was 82 h and 42 h in the 90-year and 60-year Platycladus orientalis forests, respectively. (2) The wetting front movement velocity (Vwf) and the maximum increase of soil water content (Δθmax) were obviously different between two Platycladus orientalis forests with different ages. The Vwf and Δθmax in the 90-year Platycladus orientalis forest decreased with the increase of soil depth. However, the Vwf was 6.9 cm/h faster at deeper soil depth below 50 cm than in shallower layers in the 60-year Platycladus orientalis forest. The maximum increase of soil water content was 0.021 m3/m3 higher in deeper layer below 50 cm than in shallower layer. Within soil layer of 50—100 cm, Vwf and Δθmax of 60-year Platycladus orientalis forest were both higher than 90-year Platycladus orientalis forest, with an increase of 3.3 cm/h and 0.037 m3/m3 respectively. The 60-year Platycladus orientalis forest required less rainfall amount (18.8 mm) to infiltrate into the 100 cm layer, where preferential flow occurred more frequently. (3) The increment of soil water storage (W) in 0—100 cm layer in the 60-year Platycladus orientalis forest (Maximum increment was 291 mm and 234 mm in rainy season in 2021 and 2022, respectively) was higher than in the 90-year Platycladus orientalis forest (Maximum increment was 199 mm and 167 mm in rainy season in 2021 and 2022, respectively). (4) The total rainfall amount and peak rainfall intensity were positively correlated with the response times, the maximum response depth, the maximum increase of soil water content and the wetting front movement velocity (P<0.05). They were main controlling factors that affected soil water movement processes under different rainfall events. The study can provide scientific basis for soil and water conservation, flood disaster prevention and forest ecosystem sustainable development in the upper reaches of Baiyangdian under climate change.