The prevalence of developmental delay (DD) in children worldwide is still on the rise, and its causes are complex and diverse, causing varying degrees of impact on the development of the sensory nervous system in the brain of children. Sensory integration training is a treatment method that applies sensory stimulation and comprehensive activities. It is currently widely used in children with DD. This therapy can effectively improve the development and integration of the sensory system in children with DD. It also enhances the individual’s ability to adapt to external stimuli, promoting their development in language, motor, and cognitive functions. This article explores the relevant mechanisms of sensory integration training and DD, as well as the current status and effects of its application in DD children, in order to promote the development and progress of related research fields.