In recent years, with the advancement in the field of biomedical applications, atmospheric pressure non-thermal plasma technology has shown many advantages in disinfection and sterilization. In terms of its application, the key lies in how to easily generate a large-area, uniform and stable plasma. In this work, a set of unipolar microsecond pulse array plasma jet system is developed, which can be excited to generate plasma jet under atmospheric pressure and realize large-area sterilization treatment. The system generates high-voltage pulses with a peak voltage of 20 kV and a frequency of 15 kHz. The jet is uniform and stable, covering an area of 37.7 cm², the jet length is stable at 6 cm and the jet power is 40.05 W. Treating for 5 min can basically inactivate all Bacillus subtilis spores in the area covered by the jet. The effects of different parameters on the sterilization efficiency are investigated, and the results show that the sterilization rate is positively correlated with the working voltage, pulse frequency and treatment time. The sterilization effect is better in helium atmosphere. The SEM images show that the plasma jet damaged the shell structure of Bacillus subtilis spores, hence the spores failed to metabolize normally and eventually died.