The invention provides a heat radiating pipe for a heat exchanger, which is characterized in that a refrigerant channel is formed by welding folded metal plates, the contact parts of the folded metal plates are in line contact, and at least one surface of the contact parts is provided with bulges. The invention also provides a manufacturing method for the heat radiating pipe of the heat exchanger. In the invention, the bulges are arranged on the proper position of the metal material surface, the contact parts of the folded metal materials are in a line contact state, and therefore, the contact parts are in tight contact by using pressing force generated by a strapping tape, thereby overcoming the uneven welding quality of the heat radiating pipe in the prior art, improving the welding precision of the heat radiating pipe and effectively preventing the leakage rate of the welded heat radiating pipe.