Electric field plays a key role in electrospinning process for nanofiber and nanofiber yarn producing. The electric field distribution of the yarn manufacturing system is simulated by using finite element method analysis. The effects of electric field distribution and intensity were studied to analyze the influence of the electric field on the electrospun nanofiber yarn surface morphology, mechanical, thermal and water absorption properties. The results show that the morphology and diameters of nanofiber and yarn were obviously affected by the electric field with changing the needle distance and applied voltage, which further influence the mechanical performance of the yarn. The needle distance does not much affect the thermal property of the PSA electrospun yarn, whereas the yarn obtains better thermal resistance properties at voltage of 25 kV. The nanoyarn electrospun and assembled under higher applied voltage is proved to have a better wicking property in our research.