Considering the influence of the type and content of anti-cracking admixture, the evolution of compressive strength of fly ash concrete under the conditions of curing and sulfate corrosion was studied. The test results show that the effect of UEA expansion agent is the same under different fly ash content, and the effect of HME-V high-efficiency anti-cracking agent is different. During the curing period, the compressive strength value of 30% fly ash mixed with UEA or HME-V is stable after 90 days. The best strength content is 5% and the loss of the specimen with 5% content is the lowest after sulfate corrosion. With the increase of fly ash content (10%~30%), the compressive strength at 28d of the two kinds of anti-cracking admixtures decreases. The strength of UEA specimens cured with 30% fly ash content is higher than that of HME-V specimens. After sulfate corrosion, the strength of HME-V specimens is higher than that of UEA. HME-V admixture can better delay the loss of mechanical properties caused by sulfate corrosion than UEA.