The present disclosure provides a control method of a voltage conversion circuit. The voltage conversion circuit includes a DC voltage input terminal, a primary side switch unit, a resonant inductance, a transformer, a secondary side switch unit and a DC voltage output terminal which are electrically coupled. The resonant inductance is connected to the transformer in series. The voltage conversion circuit also includes a resonant capacitance which resonates with the resonant inductance. The control method includes: controlling switch elements in the primary side switch unit and the secondary side switch unit, so that a range of a ratio Ton/Tr of a total conduction time Ton to a resonant period Tr of the voltage conversion circuit is (0, 1.8)U(2.7, 3.7)U(4.8, 5.5), and a quality factor Q of the voltage conversion circuit is less than or equal to 5, that is, Q≤5. The control method provided by the embodiment of the present disclosure can reduce the conduction loss and the switching loss of the voltage conversion circuit, thereby improving the efficiency and reducing the cost.