The invention discloses a high-voltage electrode discharge current measuring device, belongs to a high voltage measuring device, and solves the problems that the existing high-voltage current measuring device cannot measure the DC (direct current) component and is easily interfered with by high-intensity magnetic field. According to the invention, a current sensor converts a high-voltage electrode discharge current signal into a voltage signal which is converted into a digital signal by an analog/digital conversion circuit and then sent to a digital processor through a data bus; the digital processor processes the digital signal into a USB (universal serial bus) signal and sends the USB signal to an optical signal projector which converts the USB signal into an optical signal; the optical signal is transmitted to an optical signal receiver through an optical fiber; the optical signal receiver converts the optical signal into an electric signal conforming to the USB standard and outputs the electric signal through a data transmission line; and the current sensor comprises a mouse cage-type resistor array and a shielding shell sleeved outside the mouse cage-type resistor array. The device disclosed by the invention has simple structure, wide measuring band, high precision and strong anti-electromagnetic interference capability, and can measure the DC (direct current) with frequency up to 100 million Hz.