A ULCA device and a mobile terminal are provided. The ULCA device includes an RF transceiver, at least two PAs, one power-amplifier power module, a control chip, a multiplexer, and an antenna switch. The RF transceiver is connected to the at least two PAs. The at least two PAs are connected to the multiplexer, which is connected to the antenna switch. The control chip is connected to the RF transceiver and the power-amplifier power module, and configured to determine supply voltage needed by each PA, determine target voltage to be output by the power-amplifier power module based on maximum supply voltage, and send a power supply instruction to the power-amplifier power module. The power-amplifier power module is connected to the at least two PAs, and configured to regulate the target voltage according to the power supply instruction and output the target voltage to the at least two PAs.