The present invention discloses a melt impregnation device and a melt impregnation method. Through an impregnation chamber with a corrugated shape, when a resin melt-distributing runner is connected with a peak position of the impregnation chamber, a chamber vertical height of the peak position of the impregnation chamber is larger than a chamber vertical height of a trough position of the impregnation chamber, and when the resin melt-distributing runner is connected with the trough position of the impregnation chamber, the chamber vertical height of the trough position of the impregnation chamber is larger than the chamber vertical height of the peak position of the impregnation chamber. The present invention can balance an impregnating effect of a continuous fiber band, can carry a broken fiber hairiness which is generated during the impregnation out of an impregnation area, avoids a broken yarn, and enhances a production stability and a production efficiency.