The present invention provides a transmitting device and a method for determining a target predistortion setting value. The transmitting device comprises: a setting value control unit, a predistortion unit, a transmitting circuit, a receiving circuit, and a determining unit. The present invention can predistort signals before a power amplifier in a transmitting device by a method of determining a target predistortion setting value (i.e. an optimal predistortion setting value) from a plurality of candidate predistortion setting values. In this way, signals outputted by the power amplifier in the transmitting device can be adjusted to an optimal state, so as to solve the distortion problem of the outputted signals of the power amplifier.