Based on the whole and strong weathered granite subgrade of the two section of the first project on Zhuzhou city airport road, studied the soil mineral composition, fluid plasticity index and CBR(California bearing ratio) value of the whole and strong weathered granite, and concluded that the whole and strong weathered granite was not suitable for the subgrade filling and it must be improved to use. Put forward the lime improved treatment scheme to solve the problem of whole and strong weathered granite, designed the mixture ratio and presented the construction technology requirements.