The separation and concentration of blood components or biological functional microparticles, have become indispensable in various biomedical and environmental applications. In this paper, a chip with two rows of micropillar arrays along a spiral-channel, in which plasma and various blood cells with different sizes can be separated or enriched simultaneously, has been achieved. The proposed method combines crossflow, centrifugation and size-selective separation approaches. Specially, a 40 μm-high step, which can increase the pressure difference, is designed between the inner and middle channel to enhance the separation efficiency and purity. In the chip with split-level channels, the number of red blood cells (RBCs) gathered from the inner outlet decreased significantly, and the collected plasma volume increased, compared to those in the plain one.