To investigate the level of screen time and gross motor movement level and the correlation between them in left-behind children aged 3 to 6 years old in China. A randomized whole-group sampling method was used to study 817 left-behind children aged 3-6 years in 15 kindergartens in Xiangcheng city, Henan province. The third version of the Test of Gross Motor Development (TGMD-3) was used to test the children's gross motor movement level, and the screen time questionnaire was used to test the children's screen time level. The relationship between the two and the indicators was explored using Pearson's two-sided correlation and multilevel regression. The average daily screen time of left-behind children aged 3-6 years old increased with age, and the reporting rate of >2 h/d ranged from 22.43% to 33.73%; gross motor movement of left-behind children aged 3-6 years old increased with age, with significant differences between age (p<0.05). There was a low to moderate negative correlation (r = -0.133 to -0.354, p<0.05) between screen time and gross motor movement in children aged 3-6 years, and multiple regression analysis showed that screen time was predictive of gross motor movement in children (p<0.05), with an explanation rate of 21.4%. There is a correlation between screen time and gross motor movement development in children aged 3-6 years old left behind, and the gross motor movement ability of children aged 3-6 years old can be developed by reducing screen time and increasing physical activity.