A kind of electrostatic charge in electrostatic charge filter (522) removal electrocardiosignal. The electrostatic charge filter includes the first amplifier (608), and first amplifier is configured as amplification input signal, and the input signal includes the electrocardiosignal and the electrostatic charge for carrying out self-electrode, and the electrode is in the path of X-ray beam. The electrostatic charge filter further includes limiter (614), and the limiter is configured as limiting the maximum voltage of the signal based on predetermined clamp threshold value, to generate signal of the voltage through clamping. The electrostatic charge filter further includes filter (616), and the high fdrequency component that the filter is configured as the signal to the voltage through clamping is filtered, to generate the signal through filtering. The electrostatic charge filter further includes the second amplifier (620), second amplifier is configured as scaling the amplitude of the signal through filtering, so that the electrocardiosignal in output signal has voltage level identical with the voltage level of the electrocardiosignal in the input signal.
