The present invention relates to the field of high-voltage measurement in the power industry, and in particular to a novel high precision resistance-capacitance parallel voltage divider for online monitoring. The high precision resistance-capacitance parallel voltage divider for online monitoring comprises a base, wherein a composite insulator is arranged vertically upwards on the base, the interior of the composite insulator is hollow, and is arranged with a high-voltage arm; the upper end of the high-voltage arm is connected with a high-voltage connection terminal arranged at top of the composite insulator, the lower end is connected with a low-voltage arm and is matched with a shielding shell; and the shielding shell is embedded with an output terminal connected with the low-voltage arm. The devider utilizes the principle of resistor-capacitor voltage division, to convert a high-amplitude voltage signal that is difficult to measure into a low-amplitude voltage signal that is easy toobserve, adopts parallel multiple resistance-capacitance branches and selects low-inductance components to design a low-voltage arm structure to minimize stray inductance, can improve measurement precision when measuring nanosecond fast pulse signals, can add a compensation unit between the high voltage arm and the low voltage arm, and can further expand bandwidth.