Abstract: To better understand the effects of atmospheric pressure plasma on cucumber seed germination and seedling growth, the authors designed novel atmospheric pressure plasma equipment. The cucumber seeds were treated by the equipment with different voltages from 5610 V to 7310 V. The results show that the germination energy, germination percentage, germination index and vigor index were increased significantly. Compared with the control, they improved by 8.22%～52.94%, 2.21%～9.55%, 5.37%～35.32% and 4.72%～104.72%, respectively. In addition, the activities of alpha amylase were higher, and the conductivities of seeds were lower than those of the control. The plant height, stem diameter, fresh weight, dry weight, root volume, as well as root activity, chlorophyll content, and peroxidase activity were increased destinctively. The plasma treatments of 6290 V and 6630 V are better than other voltages in this experiment.