Balanced swing can make babies’ brain regulate smoothly,then can fall asleep quickly. Experiments found that using electric cradle are 2-4 minutes lesser than the traditional manual cradle for babies to fall asleep. The experts confirmed that the traditional manual swing size and speed are not stable. During the swing process, babies need constantly to adjust and reset the nevers regulation, thus prone to dizziness and regurgitate milk. While the electric cradle can automatically set the stable swing range according to the babies’ needs,which is good for protecting babies’ nervous. Therefore, the baby can sleep faster and get better sleep quality.