The invention discloses a signal conditioner. The signal conditioner comprises a current loop receiving circuit, a temperature compensation unit, a signal amplification circuit and a low-pass filter circuit, wherein the current loop receiving circuit is used for receiving monitoring signals for monitoring whether a pipeline leaks or not; the temperature compensation unit is used for determining the signal amplification gain required at the real-time environment temperature; the signal amplification circuit is connected with the current loop receiving circuit and the temperature compensation unit and used for amplifying the monitoring signals according to the signal amplification gain; the low-pass filter circuit is connected with the signal amplification circuit and used for filtering signals higher than preset frequency out of the monitoring signals. Thus, a photoelectric coupling manner is adopted for current loop receiving of the signal conditioner, on the basis that current signals output by a pressure transmitter are received and converted into voltage signals, high-reliability signal transmission and effective electric isolation of the pressure transmitter and the signal conditioner are provided, and the probability of circuit damage caused by mutual interference is greatly decreased.