The invention discloses a signal transceiver capable of reinforcing return loss in a power-off state. The signal transceiver comprises a connector, a band-pass filter, a front-end module and an impedance transformation circuit, wherein the connector is used for receiving a signal; the band-pass filter is coupled to the connector and is used for filtering the signal; the front-end module is used for demodulating the signal; the impedance transformation circuit is coupled between the band-pass filter and the front-end module and is used for converting an input impedance value of the signal transceiver; the impedance transformation circuit comprises an input end, an output end, an impedance conversion unit and a first power input circuit; the input end is coupled to the band-pass filter, and is used for receiving the signal; the output end is coupled to the front-end module, and is used for outputting the signal to the front-end module; one end of the first power input circuit is coupled to the impedance transformation unit and is used for providing a power supply; the impedance transformation unit is coupled between the first power input circuit and the input end, and is used for converting the input impedance value of the signal transceiver. According to the signal transceiver disclosed by the invention, the return loss can be effectively improved under the power-off state to improve the efficiency of a system, and the production cost of the signal transceiver can be further reduced.