The clayish crushed stone was used for making aerated concrete. Through studying hydro-thermal synthesis reaction, mix ratio, gas-forming and performance analysis, Grade-B05 and Grade-B06 aerated concrete were prepared successfully. The proper mix ratio and key processing parameters were achieved. The microstructure of aerated concrete with crush stone was analyzed by means of XRD and SEM. The experimental results indicate that the hydration products are poorly crystalline C-S-H (B), tobermorite and hydrogarnet. No component of clay was found. Unreacted SiO2 can be in existence, and the structure system of aerated concrete is homogeneous and dense.