Provided is a method of manufacturing high strength synthetic fibers, and high strength synthetic fibers manufactured using the same. More particularly, the method involves a localized heating process by raising the temperature of a molten spinning fiber to a temperature higher than that of a pack body during a short period of time with no degradation through a heating zone located in the immediate vicinity of capillary in the spinning nozzle, so as to effectively control the molecular entanglement structure in the molten polymer without reducing the molecular weight and thus to enhance the drawability of the as-spun fibers, thereby improving the mechanical properties of the as-spun fibers, such as strength, elongation, etc., using the existing processes of melt spinning and drawing and thus enabling a mass production of a high-performance fiber at low cost.