A physiological information collecting system and a transceiver device thereof are configured to collect physiological information from animal bodies. The transceiver device includes a front-end circuit, a follower circuit, a quadrature delay line and an output circuit. The front-end circuit separates a discontinuous signal into an in-phase signal and a quadrature signal. The follower circuit outputs a control voltage and rotates the in-phase signal by a predetermined phase angle to output a follower signal. The quadrature delay line rotates the quadrature signal by a corresponding phase angle according to the control voltage. The output circuit synthesizes the follower signal and the quadrature signal and outputs a data signal by demodulating the discontinuous signal. Consequently, the transceiver device reduces the bandwidth range of the discontinuous signal when receiving the discontinuous signal, reduces the power consumed by the transceiver device, and demodulates the discontinuous signal with various transmission rates of different data.