The application provides an electric field intensity measurement device and method of an electrostatic field. The device comprises an induction electrode plate, an upper pole plate, a lower pole plate, an annular channel, an electromagnetic field source module and a signal processing module. The induction electrode plate is electrically connected with the upper pole plate; the annular channel comprises a first straight channel, a second straight channel and two sections of arc channels; the first straight channel is arranged between the upper pole plate and the lower pole plate; bubbles, magnetic fluid or liquid-state metal are filled in the annular channel; at least one electromagnetic field source module is sleeved on the arc channel or the second straight channel; the electromagnetic field source module comprises a magnet, a positive plate and a negative plate; the lower pole plate is electrically connected with the signal processing module, the signal processing module is used forconverting a periodic current signal output by the lower pole plate into the periodic voltage signal, and computing the electric field intensity according to the periodic voltage signal. The electricfield intensity measurement device and method of the electrostatic field provided by the application have the advantages of being small in volume, high in measurement result reliability, stable in operation, and long in service life.