Abstract: Silty soil is of poor performance and is needed to improve before it can be used in highway subgrades. Wheat straw is environmentally friendly and renewable. When mixed with silty soil, wheat straw can play a reinforcing role, but it is easily corroded by water and can be used after corrosion protection. Based on the pore area ratio, this paper analyzes the anticorrosion mechanism and anticorrosion effect of polyvinyl alcohol on straw, the effect of anticorrosion on the tensile strength through the tensile strength test and the effect of straw on the shear strength of silty soil through the direct shear test. The results show that polyvinyl alcohol exerts its own anti-corrosion performance, fills the straw pores to reduce water absorption channels, and forms a protective film on the straw surface to block water from entering to achieve anti-corrosion. The smaller the pore area ratio, the better the anti-corrosion effect. The best soaking time for straw preservative is 4 days, and the best solution concentration for preservatives is 10%. At this time, the straw pore area ratio is the smallest, and the time for preserving is the shortest or economically optimal. The effect of the length of wheat straw on the pore area ratio is mainly within 4 days, and is not related to the final pore area ratio. The tensile strength of the anticorrosive wheat straw is increased. The cohesion of straw reinforced soil increases first and then decreases with the increase of straw content and wheat straw length. The optimal content range from 0.4% to 0.6%, and the optimal straw length is 15 mm. The internal friction angle increases slightly with the increasing straw content, but the increase is very small, and there is no obvious pattern under different lengths.