The most important process of making infant milk powder is that removing the moisture of the liquid raw milk to the maximum. But in the process of removing the moisture,the physical structure and the shape of the nutrients of the milk powder will change a lot. So choosing which way to remove the moisture has a decisive impact on the shape and the nutrients of the products. The skill of evoporation concentration to produce the infant milk powder means that evoporating in a low temperature to remove nearly 50% of the moisture and keep the nutrients in the infant milk powder to the maximum under vacuum. This paper discussed from the principles,the process and some notices of the evaporation concentration,to provide some references for the dairy enterprises.