Objective To explore the clinical rehabilitation effect of collision method on hearing-impaired children with excessively low loudness. Methods A single-subject single-baseline A-B experimental design was adopted. A hearing-impaired child with low loudness was subjected to rehabilitation training to increase the loudness using the collision method

and the average intensity

highest intensity and lowest intensity of the hearing-impaired child before and after the training were compared and analyzed. Results There were significant differences in the average speech intensity

highest intensity and lowest intensity of the hearing-impaired child before and after the collision training（P<0.05）. Conclusion The collision method has a significant effect on helping hearing-impaired children with low loudness to improve speech loudness.