Abstract:China is one of the countries with abundant reserves of aeolian sand in the world. Aeolian sand is widely distributed in North China. If the material can be taken locally in the construction of the project, that is, the aeolian sand can be used to replace natural river sand as fine aggregate to prepare concrete, which can not only promote the development of the construction industry, but also slow down the sand damage and benefit the environment. According to the actual service environment of concrete in the agricultural water conservancy projects of cold regions, the river sand was replaced by aeolian sand, and the concrete samples with different aeolian sand substitution rates were prepared. And they were used as the research objects for the freeze-thaw cycle-carbonization coupling test. An analysis was conducted on the damage process of aeolian sand concrete under the influence of freezing-thaw cycle-carbonization coupling. The relationship between the pore structure evolution of concrete and its durability was discussed by nuclear magnetic resonance instrument. The internal damage of different treatments concrete were analyzed by measuring the mass loss and dynamic elastic modulus of different periods of concrete. The test results showed that under the condition of the same number of freeze-thaw cycles and carbonization time in each test cycle, the damage caused by freeze-thaw cycle-carbonization was greater than that of carbonization-freeze-thaw cycle. With the increase in the number of freeze-thaw cycles and carbonization time, the concrete mass loss rate significantly increased while the relative dynamic elastic modulus greatly decreased; when the replacement rate of aeolian sand increased from 0 to 40%, the initial porosity of the concrete decreased, and the mass loss rate and relative dynamic modulus change in the test decreased. So the porosity of the concrete could not be used as an indicator in this test to accurately evaluate concrete durability; the pore distribution of concrete at different time was measured by nuclear magnetic resonance technology. The internal pores of concrete were divided to gel pores (0-0.05 μm), capillary pores (>0.05-1 μm), less harmful pores (>1-10 μm) and more harmful pores (>10 μm). Through the correlation analysis between the evolution of four kinds of pore proportions and the porosity and the relative dynamic elastic modulus of concrete, it was found the proportion of gel pores and less harmful pores in concrete had a dominant effect on its porosity and relative dynamic elastic modulus. When the ratio of gel pores to less harmful pores was 5 - 25, the change of the relative dynamic elastic modulus and porosity were not more than 1%; and the change of the relative dynamic elastic modulus and porosity of the concrete were change obviously when the ratio of gel pores to less harmful pores was 0-5; The addition of aeolian sand improved the pore distribution of concrete, and the aeolian sand concrete with an aeolian sand replacement rate of 40% showed a good resistance to freeze-thaw and carbonization. This study can provide a basis for the research and application of aeolian sand concrete in agricultural water conservancy projects of cold regions.