To study the effects of parent-child painting and creative crafting therapy on the core symptoms of preschool children with mild-to-moderate autism spectrum disorder (ASD) and the parenting stress and hope level of their mothers. A total of 56 preschool children with mild-to-moderate ASD and their mothers were divided into an experimental group and a control group using the block randomization method, with 28 pairs in each group. The subjects in the control group received an applied behavior analytic intervention and those in the experimental group received parent-child painting and creative crafting therapy in addition to the intervention in the control group. The intervention time was 20 weeks for both groups. Autism Behavior Checklist (ABC), Social Responsiveness Scale (SRS), Parenting Stress Index-Short Form (PSI-SF), and Herth Hope Index (HHI) were used to evaluate the core symptoms of children and the parenting stress and hope level of their mothers before and after 20 weeks of intervention. Forty-nine child-mother pairs completed the study (25 pairs in the intervention group and 24 pairs in the control group). The children in the experimental group had significantly lower scores of social interaction, language, social communication, and social motivation and total scores of ABC and SRS compared with those in the control group (P<0.05). The mothers in the experimental group had significantly lower scores of parental distress and parent-child dysfunctional interaction and total score of PSI-SF (P<0.05) and significantly higher total score of HHI and scores of each dimension compared with those in the control group (P<0.05). The combination of applied behavior analytic intervention with parent-child painting and creative crafting therapy can more effectively improve the core symptoms and social interaction of preschool children with mild-to-moderate ASD, reduce the parenting stress of mothers and improve their hope level.