Disclosed is a low-resistance reactor for synthesizing methanol, which mainly comprises a barrel, a top cover, a double-cone gasket, and a cold pipe bladder, the barrel being separated into the upper air chamber and the lower air chamber by a separator plate. The bottom of the barrel is equipped with a ceramic ball, which is equipped with a catalyst layer; and the cold pipe bladder is fixed with the separator plate. The air inlet pipe of the cold pipe bladder through the separator plate is sealed with gland housing; the raw material gas of methanol flows into the upper air chamber by air inlet pipe, and then into the cold pipe bladder after distribution, after cocurrent heat transfer and countercurrent heat transfer with the current in the catalyst layer, the gas flows into the lower air chamber, and generates the reaction of synthesizing methanol by the catalyzation of the catalyst. The reactor for synthesizing methanol applied in the process of synthesizing methanol with a high pressure (11.0- 15.0MPa) or a medium pressure (4.0- less than10.0MPa), the structure simple and the operation property well.