An atmospheric pressure helium plasma jet with a coaxial dual-channel inlet under single electrode structure (stainless steel needle tube) and double electrode structure (stainless steel needle tube—high voltage ring electrode) is comparatively studied using a two-dimensional axisymmetric fluid model. The study shows that compared with the single electrode structure, the propagation velocity of the jet decreases significantly under the double electrode structure, and decreases more in the dielectric tube. Meanwhile, the spatial structure of the jet changes significantly under the double electrode structure. Under the single electrode structure, the jet structure changes from a donut-shaped hollow structure to a solid disk-shaped structure with its development; while under the double electrode structure, a transformation process from a solid disk-shaped structure to a donut-shaped hollow structure and then to a solid disk-shaped structure is shown, which improves the uniformity of the jet spatial distribution. The effect of high-voltage ring electrode thickness on jet under the double electrode structure is also investigated. It is shown that as the ring electrode thickness increases, the jet propagation velocity decreases further and the jet channel shrinks radially, and the inner diameter of the jet with the donut-shaped hollow structure decreases, which improves the uniformity of the radial distribution of the jet.