A boost power conversion circuit, wherein the boost power conversion circuit comprises a power supply (V in ), an inductor (L), a first switch module (T1), a second switch module (T2), a first unilateral conduction component (D3), a second unilateral conduction component (D4), a flying capacitor (C fly ), and bus capacitors (C bus+ , C bus- ), the boost power conversion circuit comprises a third unilateral conduction component (D6), and the bus capacitors comprise an upper bus capacitor (C bus+ ) and a lower bus capacitor (C bus- ); the power supply (V in ), the inductor (L), the first switch module (T1), and the second switch module (T2) are connected in series sequentially to form a loop, the first unilateral conduction component (D3), the second unilateral conduction component (D4), and the bus capacitors (C bus+ , C bus- ) are connected in series sequentially, and a forward conduction end of the first unilateral conduction component (D3) is electrically connected to a positive end of the first switch module (T1); a positive end of the flying capacitor (C fly ) is electrically connected between a reverse cut-off end of the first unilateral conduction component (D3) and a forward conduction end of the second unilateral conduction component (D4), and a negative end of the flying capacitor is electrically connected to a forward conduction end of the third unilateral conduction component (D6); a reverse cut-off end of the third unilateral conduction component (D6) is electrically connected to a junction point between the upper bus capacitor (C bus+ ) and the lower bus capacitor (C bus- ), wherein the boost power conversion circuit is characterized by further comprising a third switch module (S), one end of the third switch module is electrically connected to the negative end of the flying capacitor (C fly ), and the other end of the third switch module is electrically connected to a common point between the first switch module (T1) and the second switch module (T2). the power supply (V in ), the inductor (L), the first switch module (T1), and the second switch module (T2) are connected in series sequentially to form a loop, the first unilateral conduction component (D3), the second unilateral conduction component (D4), and the bus capacitors (C bus+ , C bus- ) are connected in series sequentially, and a forward conduction end of the first unilateral conduction component (D3) is electrically connected to a positive end of the first switch module (T1); a positive end of the flying capacitor (C fly ) is electrically connected between a reverse cut-off end of the first unilateral conduction component (D3) and a forward conduction end of the second unilateral conduction component (D4), and a negative end of the flying capacitor is electrically connected to a forward conduction end of the third unilateral conduction component (D6); a reverse cut-off end of the third unilateral conduction component (D6) is electrically connected to a junction point between the upper bus capacitor (C bus+ ) and the lower bus capacitor (C bus- ), wherein the boost power conversion circuit is characterized by further comprising a third switch module (S), one end of the third switch module is electrically connected to the negative end of the flying capacitor (C fly ), and the other end of the third switch module is electrically connected to a common point between the first switch module (T1) and the second switch module (T2). <EOS>