For the study of the effect of filled core on the performance of PHC pipe pile bending, deduced the formula of flexural bearing capacity of filled core PHC pipe pile via elastic theory and superposition principle, and comparatively studied the PHC pipe piles with filled core and without filled core. The results showed that the plain concrete filled core improved the flexural bearing capacity of PHC pipe pile by about 16%, and the reinforced concrete filling core improved the capacity about 35%. It can be used as a reference for core filled PHC pipe pile design under the horizontal loading.