Abstract: The application of gravel pile composite foundation is extensive for reinforcing soft soil. In order to hold its regularity, this paper allows for the stress ratio of pile and its surrounding soil and the characteristic of pile body according to field tests and pile body stress testing of an electric factory. Stress ratio correlates with applied load, its form is a top-protruding parabola and its values are about 3~6. Through static test, the characteristic of pile stress is similar to that of natural foundation and the influencing depth is 2~3 times of loading plate. The consolidation of composite foundation is simulated by finite element method and its characteristic is that the gravel pile will not only greatly quicken the consolidation of composite-foundation but also lower the effect of post-construction settlement.