In the paper, the mechanisms of the consolidation of collapsible loess by means of column hammer pile method are analyzed on basis of the calculation methods at home and abroad. First, the loadbearing capacity of the composite ground consolidated by column hammer pile method is derived by means of elasticplastic mechanics and cylindrical cavity expansion theory; Then, the loadbearing capacity of the composite ground consolidated by column hammer pile method is measured by means of static load test and the consolidation effect and consolidation depth are verified by means of dynamic penetration test, with a case history as background; Finally, the calculation results are compared to the values specified in relevant standards and the values measured, which shows that the calculation results agree well with the results measured by static load test and that the loadbearing capacity and the consolidation depth of the composite ground can meet the design requirements. The paper can provide reference for the application of column hammer pile method in collapse loess in the future. 