This paper proposed a three-phase interleaved boost converter with a newly integrated coupling inductor that can obtain the same inductance from each phase. By core integration to reduce the volume of an inductor and decrease core loss via flux coupling. The expression ratio of coupling inductance and leakage inductance by reluctance model and effect of coupling coefficient in this thesis. For the method of winding, this paper also proposed part divided winding to obtain the symmetry inversely coupled winding which cancels dc flux and get lower inductance for high-frequency application, too. Finally, via magnetic simulation which called Magnet and tests under the condition of switching frequency 1 MHz, 50 V input voltage and 100 W output power to verify the three-phase interleaved boost converter with a novel integrated coupling inductor can get lower core loss.