A transceiver device and a power saving method thereof are provided. The transceiver device includes an attenuation estimation module, a transmitter, and a control module. The attenuation estimation module is coupled to a transmission path for estimating an attenuation value caused when a signal passes through the transmission path. The transmitter is coupled to the transmission path, for outputting a transmission signal. The control module is coupled to the attenuation estimation module and the transmitter. When the attenuation value is smaller than a default value, the output power of the transmitter is adjusted to be lower. Thereby, the power consumption of the transceiver device is decreased.