Abstract: To study the bearing capacity of construction waste composite foundation, the indoor compression test of the soil of construction waste is made in a project, the single pile and composite foundation are tested by the self-made large consolidometer, and the bearing capacity is examined through the engineering field static load testing, then the different pile length, pile diameter, composite foundation construction waste of elastic modulus was numerically simulated by using the finite element software. The results show that:The construction waste composite foundation can significantly improve the compression modulus of soft soil roadbed and its bearing capacity; Increasing construction waste of granular material pile diameter has significant effect on the reduction of the subgrade settlement and improve the bearing capacity of subgrade; The effect of the change of pile length and pile modulus on the improvement of subgrade settlement and bearing capacity is not obvious. Therefore, the construction waste composite foundation can be applied to soft roadbed treatment.