A volumetric display system with full helical screen is presented. When a series of helical slices of a 3D model is projected onto a rotating helical screen through a Digital Micro-mirror Device (DMD) as a fast Space Light Modulator (SLM), due to the persistence of vision, human observers are able to perceive a 360°viewable 3D image by fusing together the successive helical slices into a 3D image. We analyze the performance of the 3D imaging space created by a rotating helical screen, and emphasize the volexlization approach based on Enhanced Body-center Cubic (EBCC) sampling algorithm. Experimental results demonstrate that, compared with the voxelization approach based on Cartesian lattice, voxel hole avoidance and a voxel reduction of more than 30% are both achieved through utilizing EBCC sampling algorithm, and the prototype is capable of generating images with consistent brightness in a imaging space three times bigger than our former system with half screen. In the cuboid imaging space with length 400 mm, width 300 mm and height of 250 mm, 3D images can be viewed from any viewpoint without any special eyewear.