Abstract: Atmospheric pressure N₂ dielectric barrier discharge(DBD) has broad application prospects in the fields of material modification, environmental protection, disinfection and sterilization, ozone synthesis, and flow control, and discharge uniformity is very important for its application. In this paper, the effects of voltage amplitude, pulse rising/falling edge times, and repetition frequency on the uniformity and discharge process of nanosecond pulse N₂ DBD are studied by electrical and optical diagnoses. The discharge images and voltage-current waveforms are quantitatively analyzed by the Gray Value Standard Deviation method and equivalent electrical model to obtain the discharge uniformity and electrical parameters. The results show that the uniformity of N₂ DBD varies from non-uniform to uniform to non-uniform with increasing voltage amplitude or repetition frequency, and the N₂ DBD with lower frequency requires higher voltage to achieve uniform discharge. Increasing the pulse rising/falling edge times leads to a significant decrease in discharge uniformity, and the rising time has a greater impact on the discharge uniformity than the falling time. The emission spectra are measured to compare the changes of chemically active species content under different nanosecond pulse parameters. It is found that increasing the voltage amplitude or repetition frequency enhances the spectral line intensity of each N₂ particle. The increase of the pulse rising/falling edge times reduces the spectral line intensity of the main particle. This study reveals the influence mechanism of nanosecond pulse parameters on the N₂ DBD process, which is conducive to the preparation of uniform, stable and highly active plasma sources at atmospheric pressure.