A system for acquiring data of a multi-channel signal, comprising: a channel-voltage transmission module disposed in a shield room blocking electromagnetic waves, connected with a plurality of channels from which analog signals are output, and configured to generate a channel-voltage serial digital signal having information about the analog signals, and an optical fiber cable through which the channel-voltage serial digital signal is transmitted from the channel-voltage transmission module to the outside of the shield room, characterized in that, the channel-voltage serial digital signal comprises the information about the analog signals being accompanied with information about the channels from which the analog signals are output, and the channel voltage transmission module includes: an analog switch configured to select an analog signal output of a selected channel from the analog signals output from the plurality of channels; an analog-to-digital converter (ADC, 112) configured to convert the selected analog signal into a serial digital signal; a clock/counter configured to generate a channel selection digital signal for the analog switch to select a channel; and a parallel-to-serial converter configured to convert the channel selection digital signal into a serial channel selection digital signal and combine the serial channel selection digital signal with the serial digital signal to generate the channel-voltage serial digital signal. a channel-voltage transmission module disposed in a shield room blocking electromagnetic waves, connected with a plurality of channels from which analog signals are output, and configured to generate a channel-voltage serial digital signal having information about the analog signals, and an optical fiber cable through which the channel-voltage serial digital signal is transmitted from the channel-voltage transmission module to the outside of the shield room, characterized in that, the channel-voltage serial digital signal comprises the information about the analog signals being accompanied with information about the channels from which the analog signals are output, and the channel voltage transmission module includes: an analog switch configured to select an analog signal output of a selected channel from the analog signals output from the plurality of channels; an analog-to-digital converter (ADC, 112) configured to convert the selected analog signal into a serial digital signal; a clock/counter configured to generate a channel selection digital signal for the analog switch to select a channel; and a parallel-to-serial converter configured to convert the channel selection digital signal into a serial channel selection digital signal and combine the serial channel selection digital signal with the serial digital signal to generate the channel-voltage serial digital signal. an analog switch configured to select an analog signal output of a selected channel from the analog signals output from the plurality of channels; an analog-to-digital converter (ADC, 112) configured to convert the selected analog signal into a serial digital signal; a clock/counter configured to generate a channel selection digital signal for the analog switch to select a channel; and a parallel-to-serial converter configured to convert the channel selection digital signal into a serial channel selection digital signal and combine the serial channel selection digital signal with the serial digital signal to generate the channel-voltage serial digital signal.