In order to study the mechanical behavior of lime-treated soil under different loading rates, a series of monotonous three-axial compression tests are carried out under different lime contents, different loading rates, and different curing periods. The test results indicate that the lime content can significantly improve the mechanical behaviors of soil, such as shear strength and elastic modulus. On the other hand, three-axial compression test of soil is carried out under the loading rate ranging from 0.1%/min to 8%/min. Experimental results indicate that the mechanical behavior of lime-treated soil is sensitive to loading rate. Besides, the corresponding relationship between internal friction angle, cohesion, lime content, and loading rate is discussed. The results indicate that the loading rate almost has no influence on internal friction angle but significant influence on lime content. Cohesion is affected by lime content and loading rate. Shear strength, elastic modulus, and cohesion all increase with the increase of loading rate. Longer curing period is associated with greater parameter value. Shear strength, elastic modulus, and internal friction angle all firstly increase and then decrease when lime content increases, which all reach the maximum at 6%.