The invention relates to an experimental apparatus for acquiring large-area uniform discharge plasmas, which belongs to the technical field of plasmas. The experimental apparatus comprises a bipolar nanosecond pulse power supply, a reactor, multi-needle-to-plate electrodes, a gas distribution system, a spectral measurement system and a discharge measurement system, wherein the bipolar nanosecond pulse power supply drives dielectric barrier discharge of air and other gas mixtures among the multi-needle-to-plate electrodes in the reactor, and the gas mixtures are input to the reactor through the gas distribution system; the spectral measurement system collects photonic information of plasma discharge in real time and inputs the photonic information to a computer for spectral analysis; and the discharge measurement system collects discharge voltage and current of the high-voltage nanosecond pulse power supply in real time, and the discharge voltage and current are displayed through a digital oscilloscope. By virtue of the bipolar nanosecond narrow-pulse power supply, the large-area discharge plasmas are generated without a magnetic field; and the generated plasmas are uniform, diffusive, high in electron density, high in energy utilization ratio, low in energy consumption and easy to control in a discharge process.