The invention discloses a powdered milk box and a powdered milk blending device. The powdered milk box comprises a box body, a box bottom and a second connecting mechanism. The upper portion of the powdered milk box can be connected with a pacifier and can be connected with a milk bottle through the second connecting mechanism. The powdered milk box has a powdered milk outlet. The box body can move longitudinally relative to the milk bottle connected with the powdered milk box to make the powdered milk box have a first working station and a second working station. In the first working station, the powdered milk outlet is closed, and the box body and the box bottom together form a powdered milk containing cavity isolated from water in the milk bottle. In the second working station, the powdered milk outlet is open, the milk bottle is communicated with the pacifier via the powdered milk box, and a liquid milk channel isolated from the outside in a sealed manner is formed. The powdered milk blending device includes a milk bottle and the above powdered milk box. When using the device, a user prepares water and powdered milk in advance, and then only one step is needed for blending, that is to say, the box body is made to move relative to the milk bottle. Troubles of the prior that the user has to dismount the powdered milk box after powdered milk is poured to reconnect the pacifier with the milk bottle are avoided. The powdered milk box and the powdered milk blending device are quite convenient to use, and powdered milk will not be left.