The present study is the first to describe the modeling of the morphology development of helical structures in melt-blown and electrospun fibers by calculating the intrinsic curvature within the bicomponent fibers. The theoretical model incorporates a physical model for the intrinsic curvature of the bicomponent jet with jet dynamics in the applied physical fields. We study the mechanical behaviors responsible for intrinsic curvature due to the non-uniform stretch of the bicomponent jet. Based on this model, we report on the development of intrinsic curvature of melt-blown PP/TPU and electrospun CA/TPU fibers. Several parameter effects on the intrinsic curvature are predicted by virtue of this model, which suggests the fabrication control of helical micro/nanofibers.