Babies always cry when they want to sleep mainly for the following reasons: 1st, may be the lack of some trace elements, such as lower blood calcium leads to brain nerve excitement, the baby will appear sleep restlessness, easy to cry symptoms, then you need to supplement vitamin D and calcium supplement, the treatment effect is good. No. 2, the baby sleeps when the environmental factors are too cold or too hot, will also cause before bed will cry, indoor temperature is best between 26-28 ℃, humidity at about 40%-60%. No. 3, indigestion, pent-up food, eating too much before bedtime, fire, can also cause the baby to cry, you can rub the tummy clockwise, 2-3 hours before bedtime to feed the baby some porridge, noodles and other easily digestible food, avoid spicy food, you can also drink some intestinal probiotics, regulate the baby’s intestinal flora.