The invention discloses a 
chemical reaction system for producing 
oxalic acid diester and 
oxalic acid as main products by using 
sodium formate as raw materials. The 
chemical reaction system comprises a first reaction unit, a second reaction unit and a third reaction unit, wherein the 
sodium formate is subjected to 
dehydrogenation reaction to generate 
sodium oxalate in the first reaction unit; in the second reaction unit, the 
sodium oxalate is mixed with solvents, then, the 
oxalic acid is added, the reaction is carried out, and then, the 
solid and liquid separation is carried out, wherein the 
solid phase is 
phosphate, and the oxalic acid diester is rich in the 
liquid phase; and in the third reaction unit, the oxalic acid diester-rich 
liquid phase is subjected to 
distillation separation, then, the oxalic acid diester is respectively subjected to 
hydrolysis, 
hydrogenolysis and ammonolysis, and oxalic acid, 
alcohol, glycol and 
oxamide are obtained. The 
chemical reaction system disclosed by the invention has the advantages that the influence on environment is avoided, the environment problems of lead-containing 
sewage and other waste 
discharge do not exist, phosphates from sodium ions and with higher 
additional values are generated, the process separation becomes simple, the implementation is easy, and the production process reaches the requirements of clean production and energy saving environment-friendly type production process.