Abstract: This paper presents an analysis on the failure mode and failure mechanism of steel fiber-reinforced high-strength concrete (SFHSC) four-pile caps based on flexural experiments. By the test results, we have selected three failure mechanisms for detailed analysis and derived formulas for plastic calculation of flexural capacity of this structure under the three mechanisms using yield line theory, with the effect of the characteristic values of steel fiber contents included in the formulas. Comparison shows a good agreement of the flexural capacity of the structure calculated by the formulas with measurements. The results would lay a basis for the design and application of SFHSC pile caps.