The invention discloses a manufacturing system for a melt-spinning spandex slice, comprising a mass flowmeter and a metering pump for measuring raw materials; a double screw extruder is arranged behind the metering pump, a fused mass filter, a fused mass supercharge pump, an underwater pelleting device, a molecular sieve closed cycle drying device are sequentially arranged behind the double screw extruder; the invention is further provided with a process controlling system and a process quality controlling system for controlling a reaction process. The manufacturing system for a melt-spinning spandex slice has high precision and good reliability.