The paper has studied the effect of coagulation process on the structure and property of polyacrylonitrile nascent fibers during dry jet wet-spinning. The coagulation process to form polyacrylonitrile fibers has been studied by examination of FTIR, XRD, and SEM and so on. The results indicated that compared with coagulation directly, polyacrylonitrile nascent fibers gradually formed with fine crystallites and high degree of crystallization were achieved, the flex vibration peak of S=O gradually decreased, and less solvents remained in the nascent fibers with compact cross section morphology. At the same time, nascent fibers with less DMSO under different draw ratios showed higher fracture intensity and lower elongation.