<p>Socio-emotional competence (SEC) fosters children’s long-term physical, mental, and academic development. However, despite the widespread use of physical activities in child development, limited research exists on how these activities enhance children’s SEC. This study aimed to examine the impact of 5&#xa0;weeks of play-based physical training on the children’s SEC in the preschool context. In this quasi-experimental study, 153 preschoolers were divided into a physical training group (<i>N</i> = 76) and a control group (<i>N</i> = 77). The intervention group participated in 5&#xa0;weeks of physical training, consisting of 30-min weekly sessions, while the control group continued their regular daily activities. Results showed that after the intervention, the intervention group demonstrated significantly improved abilities in regulating negative emotions (<i>F</i> (1147) = 7.243, <i>p</i> &lt; 0.05, <i>η</i>^<i>2</i> = 0.054) and performing in the emotional-stroop task (<i>F</i> (1147) = 3.969, <i>p</i> &lt; 0.05, <i>η</i>^<i>2</i> = 0.026), compared to the control group, which showed no such improvement. These findings suggest that even a 5-week play-based physical training can effectively promote the development of SEC in preschool children.</p>