Objective To investigate the development characteristics of skinfold thickness and body composition of Miao students aged 7 to 15 in Xiangxi prefecture, so as to provide reference for improving physique of minority students. Methods A total of 1 064 Miao students aged 7 to 15 in Xiangxi prefecture were randomly selected by a stratified cluster method from October to November in 2019. Height, weight and the thickness of triceps skinfold (TS), subscapular skinfold (SS) and abdomen skinfold (AS) of students were measured. Body composition was estimated according to Changling and Brozek formulas. Results With the increase of age, the skinfold of Miao students gradually thickened, and the increase was obvious after 13 years old for boys and 12 years old for girls. TS, SS and AS of girls were thicker than those of boys at 8 years old (t=2.659, 2.392, 2.264, P<0.05), 11 years old (t=3.317, 3.251, 3.179, P<0.05), 13 years old (t=5.196, 3.943, 4.651, P<0.05), 14 years old (t=5.941, 4.630, 3.228, P<0.05) and 15 years old (t=4.822, 4.292, 3.210, P<0.05). The average body fat percentage, fat mass and index of female students were higher than those of male students (P<0.05 or <0.01). The age change curves of lean body mass and its index of male and female students gradually increased and crossed twice. Except for body fat percentage of male students, body composition and skin fold thickness were significantly positively correlated with age (P<0.01). Compared with the eight ethnic groups, the thickness of TS of Miao male (9.22 mm) was closer to that of Inner Mongolian Daur, and the thickness of SS (7.33 mm) was close to that of Nujiang Nu. While the thickness of TS of female (11.98 mm) was closer to that of Inner Mongolian Daur, and the thickness of SS (9.35 mm) was closer to that of Guangdong Yao. Conclusions The development of skin fold thickness and body composition in rural students of Miao nationality in Xiangxi prefecture of Hunan province conform to the general rule of growth and development. The subcutaneous fat content is relatively less, and there are gender and age differences.