Abstract: The field tests on new precast circular-plate pile caps in the CFG pile composite foundation of high-speed railway were carried out. The results show that the bearing capacity of pile caps is dependent on their flexural behavior. The flexural cracks develop in diameter directions on the top surfaces of the caps,while extend downwards on the side faces,with wide upper part and narrow lower part. The calculated flexural cracking loads are consistent with the field test results,which indicates that the FLAC model and the simplified method in this paper are effective. All of the four types of pile caps can satisfy the load-bearing capacity requirements,and the safety factors are 1.33,1.76,2.38 and 3.11,respectively.