A resonant converter apparatus includes a first pre-regulator, a first resonant converter, a second pre-regulator, a second resonant converter and a controller. The first pre-regulator receives a first input voltage and generates a first output voltage. The first resonant converter receives the first output voltage and generates a supply voltage. The second pre-regulator receives a second input voltage and generates a second output voltage. The second resonant converter receives the second output voltage and generates the supply voltage, in which an output of the second resonant converter is electrically connected in parallel with an output of the first resonant converter. The controller controls the first pre-regulator and the second pre-regulator such that the first resonant converter and the second resonant converter generate identical output currents in accordance with controlled operations of the first pre-regulator and the second pre-regulator. A control method for a resonant converter apparatus is also disclosed herein.