The invention relates to a can-type heat exchanger. The can-type heat exchanger may include a housing having a space therein, integrally formed with a mounting portion, and a first inlet and a first outlet; a partition wall integrally formed to the housing, separating the space and the inside of the mounting portion, and forming a bypass passageway inside of the housing; a heat radiating unit inserted into the space, provided with connecting lines alternately formed by stacking a plurality of plates, ; a cover cap mounted at opened one surface of the housing, and a second inlet and a second outlet for communicating a second connecting line of the connecting lines ; and a valve unit mounted at the first inlet formed in the mounting portion and penetrating the partition wall in the mounting portion, selectively opening and closing the space or the bypass passageway separated by the partition wall using linear displacement.