Left-behind children, as a particular group, often face profound psychological issues such as emotional loss and psychological anxiety. In response to these challenges, art therapy, with its innovative psychological intervention approach and integration of humancomputer interaction elements, has paved new paths for the psychological growth of left-behind children. This study delves into this trend, constructing an interactive art-based group counselling model through practical activities and interactive experiences to guide left-behind children toward psychological well-being. This study conducted a long-term group art therapy intervention for 43 left-behind children in a rural school, using the Tree-Drawing Technique for digital painting. Through the painting analysis of the pre-test and post-test of the intervention, we found that our art intervention had a significant effect on children’s positive psychology.