The utility model provides a heat transfer tube and a heat exchanger adopting the same. The heat transfer tube comprises a plurality of parallel outer tubes (13), a plurality of parallel inner tubes (15), clearance supporting members (17) and supporting members (19), wherein the inner tubes (15) are inserted into the outer tubes (13) and two ends of each inner tube (15) stretch out of each outer tube (13); the clearance supporting members (17) are configured in the clearances of the inner circumferential surfaces of the outer tubes (13) and the outer circumferential surfaces of the inner tubes (15) and comprise wire rods distributed on the whole outer tubes (13) and spirally contacted with the inner circumferential surfaces and the outer circumferential surfaces; the supporting members (19) comprise wire rods distributed on the whole inner tubes (15) and spirally contacted with the inner circumferential surfaces of the inner tubes (15); the area ration of a preliminary flow path in each inner tube (15) and a secondary flow path in each outer tube is 1-1 to 1- 1.6. The heat transfer tube provided by the utility model can assemble the outer tubes and the inner tubes in the heat exchanger with high precision, and low heat transfer efficiency is not caused.