Curing agent is often used to enhance the mechanical properties of soil when clay sites are encountered in engineering construction. In this paper, the mechanical properties of silty clay reinforced by straw-polyvinyl alcohol (0% , 0. 5% , 2. 0% , 3. 0% , 4. 5% , mass fraction) under dry-wet cycle were studied. The microscopic analysis was carried out by means of electron microscope scanning test and IPP software. The results show that when the concentration of polyvinyl alcohol is 2% , the polyvinyl alcohol (PVA) solution fills the pores, wraps the soil particles, and the mechanical properties of soil are the best under different dry-wet cycles.