Provided is a low-noise amplifying circuit and a receiver, relating to the field of communications, able to filter an out-of-band block signal and prevent the out-of-band block signal from entering the receiver, thereby reducing the risk of circuit saturation of a front end of the receiver. The low-noise amplifying circuit comprises: an input end, a main signal channel, a feedback loop and an output end. The feedback loop comprises a switching capacitor array, a first amplifier, a second amplifier, a first matching loop and a second matching loop. One end of the switching capacitor array is connected to the input end. The other end of the switching capacitor array is connected to one end of the first amplifier. The other end of the first amplifier is connected to one end of the second amplifier. The other end of the second amplifier is connected to the output end. One end of the first matching loop is grounded. The other end of the first matching loop is connected to the input end. One end of the second matching loop is connected to the input end. The other end of the second matching loop is connected to the other end of the switching capacitor array.