Depth-fused multi-focal-plane display was proposed to create a fixed-viewpoint volumetric display capable of rendering correct or nearly-correct focus cues in a stereoscopic display through a small number of discretely placed focal planes. It may effectively address the negative effects of conventional stereoscopic displays on depth perception accuracy and visual fatigue due to the lack of focus cues. In this paper, we presented the design and assessment of a novel depth-fused six-focal plane display prototype, capable of rendering nearly-accurate focus cues for a depth range of 3 diopters with high image quality at flicker-free speed. The optical system design, prototype implementation and demonstration, and experimental assessment of the prototype were discussed in detail.