Disclosed is a method for methanol synthesis using synthesis gas obtained from reforming of natural gas with carbon dioxide. First, synthesis gas is obtained from steam carbon dioxide reforming of methane, in which steam reforming of natural gas is carried out simultaneously with carbon dioxide reforming of methane, by using a catalyst (Ni/Ce/MgAlOx, or Ni/Ce—Zr/MgAlOx) and processing condition capable of maintaining a predetermined ratio of carbon monoxide, carbon dioxide, and hydrogen [H2/(2CO+3CO2)=0.85-1.15]. Next, methanol synthesis is carried out by using the obtained synthesis gas and a catalyst system suitable for methanol synthesis with minimum byproduct formation (a catalyst system including a Cu—Zn—Al oxide containing CuO, ZnO, and Al2O3 at a predetermined ratio in combination with a cerium-zirconium oxide obtained by a sol-gel process). In addition, unreacted synthesis gas remaining after the operation of methanol synthesis is recycled efficiently to improve the carbon availability (methane and CO2 availability) and energy efficiency in the overall process.