Objective To analyze the differences in static balance plantar pressure characteristics between female adolescent idiopathic scoliosis (AIS) patients with moderate Lenke 3CN and healthy adolescents of the same age, and provide a scientific basis for scoliosis screening, assessment, treatment, and prognosis evaluation. Methods A total of 30 female patients with moderate Lenke 3CN AIS as the AIS group and 30 healthy female adolescents of the same age as the control group were selected, respectively. The plantar pressure data of the subjects were collected, and the characteristics of equilibrium plantar pressure distributions in two groups were comparatively analyzed. Results Regarding the plantar pressure characteristics, the average pressure (P<0.05) and hindfoot pressure (P<0.05) of the left and right foot in the AIS group were significantly greater than those of the control group, the forefoot pressure was significantly lower than that of the control group (P<0.05), and the symmetry index (SI) of both feet was significantly greater than that of the control group (P<0.05). The plantar pressure of the left foot in the AIS group was significantly larger than that of the control group in the medial mid-foot area and 1st toe area (P<0.05), and significantly smaller than that of the control group in the 1st, 2nd, 3rd, 4th and 5th metatarsal areas (P<0.05); the plantar pressure of the right foot in the AIS group was significantly greater than that of the control group in the medial heel area and the1st toe area (P<0.05), and significantly smaller than that of the control group in the lateral mid-foot area, the 3rd, 4th, 5th metatarsal area and 3rd, 4th, 5th toe area (P<0.05); and the plantar pressure in the right foot of the AIS group was significantly smaller than that of the control group in the medial heel area and 1st toe area (P<0.05). The plantar pressures at lateral midfoot area, the 3rd, 4th, 5th metatarsal area and the 3rd, 4th, 5th toe area of the right foot were significantly larger than those of the control group (P＜0.05). Regarding the center of pressure (COP), the length of the COP trajectory, the ellipse area of the 95% confidence interval, the maximum distance of COP left-right movement (COP-X), and the maximum distance of COP anterior-posterior movement (COP-Y) of the AIS group were significantly larger than those of the control group (P<0.05). Conclusions There are significant differences in static balance plantar pressure characteristics between female AIS patients with moderate Lenke 3CN and healthy female adolescents of the same age, with foot pressure favoring the side of the lateral convexity, poorer symmetry and stability of the feet, and weaker balance control.