The bearing behavior of lime-soil pile and plain concrete pile multi-type-pile composite foundation is researched. The tests are carried in a model casing of 150 cm × 100 cm × 100 cm，including fulfilled subgrade， lime-soil pile composite subgrade，plain concrete pile composite subgrade，lime-soil pile and plain concrete pile composite subgrade( 4 pile type) ，lime-soil pile and plain concrete pile composite subgrade( 9 pile type) . In the test，the dial indicator is used to measure displacement and the pressure cell is used to measure the soil stress between piles in multi-type-pile composite foundation. By comparing load test results and analysis each element’s stress distribution in composite foundation，the characteristics of multi-element composite foundation and its design formula were discussed. Analysis shows that: the working performance of multi-element composite foundation is not only related with the properties of pile and soil between piles，but also the stiffness of the foundation. parameter λ1 is from 0. 7 to 1，parameter β is from 0. 5 to 0. 9 in multi-element composite foundation bearing capacity formula．
