A heat exchange device, comprising a housing and a heat exchange core, wherein a chamber is formed in the housing, the heat exchange core is partially or completely accommodated in the chamber; a first fluid channel is formed in the heat exchange core, and the first fluid channel is isolated from the chamber; and wherein the heat exchange device is further provided with a connecting block, the connecting block is provided with a first channel, a second channel, a first connecting port in communication with the first channel, and a second connecting port in communication with the second channel; the connecting block is further provided with a first insertion hole of the first channel corresponding to the first channel and a first insertion hole of the second channel corresponding to the second channel; the heat exchange core comprises at least one flat tube, at least a part of the first fluid channel is located in the flat tube; at least a part of one end of the flat tube extends into the first insertion hole of the first channel and is mounted to the first insertion hole of the first channel in a sealed manner, and the first channel is in communication with the first fluid channel of the flat tube; and, at least a part of another end of the flat tube extends into the first insertion hole of the second channel and is mounted to the first insertion hole of the second channel in a sealed manner, and the second channel is in communication with the first fluid channel of the flat tube; the housing comprises an outer housing and a partition member, and the partition member is arranged in the outer housing, to allow a first chamber, a second chamber and a third chamber to be formed in the housing; the partition member comprises a first partition wall, a first wall portion and a second wall portion, the first wall portion is located between the first chamber and the third chamber, the second wall portion is located between the second chamber and the third chamber, and the first partition wall is located between the first chamber and the second chamber; at least a part of the first fluid channel is located in the flat tube, the flat tube comprises a plurality of straight portions, a plurality of first bending portions and a plurality of second bending portions, and fins are arranged between the straight portions; and the first bending portions are away from the mounting plate, the second bending portions are close to the mounting plate; and characterized in that, the housing is further provided with a third connecting port and a fourth connecting port, and the third connecting port and the fourth connecting port are in communication with the chamber; the first wall portion is provided with a first communication hole, the first chamber is in communication with the third chamber through the first communication hole, the second wall portion is provided with a second communication hole, and the second chamber is in communication with the third chamber through the second communication hole; and each of the straight portions comprises a first finless region provided with no fins which is located at an end close to the first bending portions, a first through-flow region is formed between two adjacent first finless regions, and a projection of first through-flow regions on the first wall portion partially or completely overlaps with the first communication hole.