Objective: To explore the application effect of intramuscular plaster in the treatment of children with thumb adduction. Methods: Sixty cases of children with spastic cerebral palsy with thumb adduction were selected as the research subjects. The control group (n=30) received routine rehabilitation training, and the observation group (n=30) was treated combined with intramuscular plaster. The clinical efficacy, abduction angle of carpometacarpal joint of thumb, fine motor ability, muscle tension of adductor muscle group of thumb and daily motor level of the 2 groups were observed. Results: After treatment, the total effective rate in the observation group was significantly higher than that of the control group (93.33% and 73.33%) (P<0.05); After treatment, the ROM, FMFM, FMQ in both groups were significantly increased, and MAS was significantly decreased, and the above indicators improved more significantly in the observation group (all P<0.05). Conclusion: Intramuscular plaster has a good effect in the treatment of children with thumb adduction, which can effectively reduce the muscle tension of adductor muscle group, improve the extension function of affected thumb and fine motor function of hand.