The invention relates to a cold-sealed degreasing furnace pipe with real-time temperature control and a degreasing method. The degreasing furnace pipe comprises a furnace pipe assembly, an intake system, an exhaust system, a cold-sealed water jacket and a thermocouple; an intake pipe of the intake system is provided with multiple air holes; the exhaust system comprises a horizontal exhaust branch pipe, a grease collecting tank and a vertical exhaust branch pipe; the grease collecting tank is in threaded connection with the horizontal exhaust branch pipe and the vertical exhaust branch pipe; the cold-sealed water jacket is provided with a water inlet and a water outlet; and a thermosensitive part of the thermocouple is positioned in the furnace pipe assembly. The cold-sealed degreasing furnace pipe improves the temperature control precision through real-time temperature control, adopts the grease collecting tank to relieve the air way blockage, effectively controls the degreasing blank components, and reduces such defects as degreasing blank cracking and deformation; and the cold-sealed degreasing furnace pipe is simple in structure, low in cost, high in operability, excellent in tightness, high in temperature control precision, safe and reliable, and is suitable for a powder injection molding thermal degreasing process.