<p>Soil salinization has become a global issue under the pressure of climate change and human activities. Desiccation cracking in saline soils further degrades the engineering and agricultural properties. However, the mechanism of desiccation cracking in saline soils, especially the effect of salinity and salt precipitation on the dynamic cracking process, is still unclear. This study compares the drying and cracking processes of kaolin and bentonite under different NaCl concentrations varying from 0 to 2&#xa0;M to investigate the impact of pore-fluid salinity on crack behavior. Mercury intrusion porosimetry, zeta potential test, and scanning electron microscopy provide additional information on clay-electrolyte interactions and soil microstructures. Results show that the drying and crack development of two clays can be divided into three stages. The crack initiation water content is close to its liquid limit and correlates well with the zeta potential. The crack initiation water content of bentonite is greatly affected by the salt concentration compared with kaolin. The variation of critical crack parameters for bentonite corresponds to a larger water content interval than that of kaolin. At high pore-fluid salinities, a salt crust forms on the surface of bentonite and masks the extensively cracked soil observed from below, which has not been observed for kaolin. Microstructure analysis suggests that the distinct cracking behavior is greatly affected by the forms of salt precipitation, which may be influenced by the saturation state of the soil as well as the pore size. Results are relevant to the understanding and control of desiccation cracking and soil degradation in saline-alkali soil areas.</p>