A power factor correction (PFC) power conversion apparatus and a power conversion method thereof are provided. In the invention, by switching a detection switch disposed inside a control chip and connected to a detection pin of the control chip at a certain time, and performing a detection of an input voltage received by a boost power conversion circuit at the certain time through a collocation between a current detection auxiliary circuit and a current detection main circuit. Accordingly, an over current protection (OCP) point corresponding to whether an OCP mechanism is activated is compensated according to the detected result, and thus the detection manner of the OCP performed by the invention can be adaptively suitable for different input voltages. In the invention, according to the detected result, a brown out protection also can be performed, and the output of the boost power conversion circuit also can be changed or determined.