Objective: To analyze the clinical effect of sensory integration training combined with cognitive training in the rehabilitation treatment of children with mental retardation. Methods: A total of 120 children with mental retardation who received rehabilitation intervention in our hospital from January 2022 to December 2025 were selected and divided into a control group and an experimental group, with 60 children in each group. The control group adopted a conventional rehabilitation training program; the experimental group adopted a combined sensory integration training and cognitive training program. The sensory integration ability, cognitive function, and daily living skills of children in the two groups were compared. Results: The sensory integration ability score of the experimental group (85.3 ± 6.2) was significantly higher than that of the control group (72.1 ± 7.5) (p < 0.05); the cognitive function score (88.7 ± 5.8) was significantly improved compared with that of the control group (76.4 ± 6.9) (p < 0.05); the daily living skills score (90.2 ± 4.7) was significantly higher than that of the control group (80.5 ± 5.3) (p < 0.05). The social interaction ability of the experimental group reached 92.5%, which was significantly higher than that of the control group (81.3%) (p < 0.05). Conclusion: Sensory integration training combined with cognitive training demonstrates favorable outcomes in the rehabilitation treatment of children with mental retardation, exhibiting a notable neurofunctional remodeling effect. It can optimize the multidimensional rehabilitation process, effectively enhance the comprehensive developmental potential of children, and hold significant clinical application value.