Disclosed is a compound 
decarburization solution for removing 
carbon dioxide in 
natural gas and a preparation method thereof. The compound 
decarburization solution comprises, by weight, 28.0% to 55.0% of N- 
methyl diethanolamine, 4.0% to 12.0% of an activating agent, 0.1% to 2.0% of a 
corrosion inhibitor, 0. 02% to 0.2% of a stabilizing agent, and 0.01% to 0.1% of a defoaming agent, with the balance being water. The preparation method includes feeding 
nitrogen into a reaction still before preparation; setting the temperature of the reaction still, adding the N- 
methyl diethanolamine and the water and stirring the mixture; adding the activating agent, the 
corrosion inhibitor, the stabilizing agent and the defoaming agent into the reaction still; stirring the mixture till the mixture is uniform, and performing 
discharge to obtain the product compound 
decarburization solution. According to the compound decarburization solution for removing 
carbon dioxide in 
natural gas and the preparation method thereof, the preparation process is protected by the 
nitrogen; the compound decarburization solution has the advantages of being high in absorption load of 
carbon dioxide, low in 
corrosion, high in thermo-stability, little in degradation loss and low in regeneration 
power consumption, and capable of obtaining purified 
natural gas and high-purity carbon dioxide while used in the 
natural gas processing; the whole process is protected by the 
nitrogen in the preparation, and 
oxygen is prevented from contacting with the solution, accordingly, risks of solution degradation and ineffectiveness of the stabilizing agent are reduced, and the 
oxygen content and the corrosion of decarburization devices are decreased.