A front-end measuring system of an automatic external defibrillator, comprising: two electrodes ; a carrier wave driving circuit configured to amplify a generated alternating current signal and output an amplified alternating current signal to the two electrodes ; a sampling circuit that comprises at least one sampling channel, wherein the at least one sampling channel is a shared sampling channel, the shared sampling channel is a measuring channel shared for measuring at least two different kinds of measured parameters, the measured parameters are selected from a patient impedance, an ECG waveform data, and a pace pulse, the shared sampling channel comprises a difference amplifier and an analog-to-digital converter , two input ports of the difference amplifier are coupled to the two electrodes respectively, and an output port of the difference amplifier is coupled to the analog-to-digital converter , the analog-to-digital converter is configured to convert an input analog signal to a digital signal by sampling the input analog signal with a predetermined sampling rate and then output the digital signal, the predetermined sampling rate of the analog-to-digital converter is greater than or equal to a maximum sampling rate of the at least two different kinds of measured parameters measured with the shared sampling channel; and a processor , coupled to the sampling circuit , which is configured to generate the alternating current signal, output the generated alternating current signal to the carrier wave driving circuit , receive the digital signal output by the sampling circuit , and extract a digital signal according to a sampling rate and an accuracy required by the measured parameters. two electrodes ; a carrier wave driving circuit configured to amplify a generated alternating current signal and output an amplified alternating current signal to the two electrodes ; a sampling circuit that comprises at least one sampling channel, wherein the at least one sampling channel is a shared sampling channel, the shared sampling channel is a measuring channel shared for measuring at least two different kinds of measured parameters, the measured parameters are selected from a patient impedance, an ECG waveform data, and a pace pulse, the shared sampling channel comprises a difference amplifier and an analog-to-digital converter , two input ports of the difference amplifier are coupled to the two electrodes respectively, and an output port of the difference amplifier is coupled to the analog-to-digital converter , the analog-to-digital converter is configured to convert an input analog signal to a digital signal by sampling the input analog signal with a predetermined sampling rate and then output the digital signal, the predetermined sampling rate of the analog-to-digital converter is greater than or equal to a maximum sampling rate of the at least two different kinds of measured parameters measured with the shared sampling channel; and a processor , coupled to the sampling circuit , which is configured to generate the alternating current signal, output the generated alternating current signal to the carrier wave driving circuit , receive the digital signal output by the sampling circuit , and extract a digital signal according to a sampling rate and an accuracy required by the measured parameters. <EOS>