A system for measuring a charge-to-mass ratio of an electrostatic atomization nozzle, comprising an electrostatic atomization nozzle, an insulating bracket, an upper cylinder, a water retaining ring, a vortex breaker, a flow regulating plate, a lower cylinder, a lower-cylinder water outlet pipe, an ammeter, a metal conducting wire, a liquid level tube, an ultrasonic level meter, a water storage tank, a water supply pipe, a liquid pump, a branch pipeline, a pressure regulating valve, a throttle valve, a filter, a flowmeter, and a computer, characterized in that the upper cylinder is formed by circumferentially connecting a gradually expanding upper-cylinder end cover and a thin-walled columnar upper-cylinder main body, a lower end of the upper cylinder is an opening, an upper end of the upper cylinder is the upper-cylinder end cover, and an end-cover central hole is provided at a center of the upper-cylinder end cover; the lower cylinder is formed by circumferentially welding a thin-walled columnar lower-cylinder main body and a gradually reducing lower-cylinder bottom cover, an upper end of the lower cylinder is an opening, and a lower end of the lower-cylinder bottom cover is connected to the lower-cylinder water outlet pipe; the upper cylinder and the lower cylinder are connected through an upper-cylinder flange and a lower-cylinder flange, thereby forming an internal cylindrical space with two open ends between the upper cylinder and the lower cylinder; the electrostatic atomization nozzle, the upper cylinder, and the lower cylinder are sequentially connected from top to bottom, and the electrostatic atomization nozzle is mounted in middle of the end-cover central hole and sprays charged droplets vertically downward; the ammeter is connected to the lower-cylinder flange through the metal conducting wire, and is capable of measuring in real time a current produced by the charged droplets sprayed by the electrostatic atomization nozzle into the lower cylinder; the charged droplets sprayed by the electrostatic atomization nozzle are gathered in the lower cylinder, and under influence of its own gravity, the liquid flows to the water storage tank through the lower-cylinder water outlet pipe, while a bottom end of the water storage tank is communicated with the water supply pipe and the liquid pump, enabling the liquid in the water storage tank to be delivered by the liquid pump to an inlet of the electrostatic atomization nozzle and again sprayed into the lower cylinder by the electrostatic atomization nozzle; the water supply pipe is communicated with the branch pipeline, and a part of the liquid delivered by the liquid pump flows back to the water storage tank through the branch pipeline; the liquid level tube is L-shaped and consists of a horizontal short tube and a vertical long tube which have thin-walled round tubular structures, the horizontal short tube is communicated with the lower cylinder, and the ultrasonic level meter is mounted on an upper end of the vertical long tube and is capable of measuring in real time a liquid level height in the liquid level tube and the lower cylinder; the ammeter, the ultrasonic level meter, and the flowmeter are connected to the computer through data cables, and the computer acquires and processes in real time measurement data of the ammeter, the ultrasonic level meter, and the flowmeter, thereby achieving real-time measurement and monitoring of the charge-to-mass ratio parameter of the electrostatic atomization nozzle.