A gradient control method of fused salt chlorination system temperature adopts a fused salt chlorination temperature gradient control system. The fused salt chlorination temperature gradient control system comprises a fused salt chlorination furnace, a 1# dust collector, a 2# dust collector, a 1# titanium tetrachloride elution tower, a 1# titanium tetrachloride elution circulating tank, a returnedfused salt chlorination furnace slurry control valve, a returned 1# dust collector slurry control valve and a returned 2# dust collector slurry control valve; during the production process, a fused salt chlorination furnace outlet temperature of the fused salt chlorination temperature gradient control system is controlled at 450-650 DEG C; the temperature of the 1# dust collector outlet is 350-400 DEG C, and the temperature of the 2# dust collector outlet is 180-230 DEG C. The gradient control method has the advantages of being simple in technique and easy to operate; high-boiling-point chloride impurity in the gas generated through fused salt chlorination furnace can timely discharge out of the system, thereby preventing excessive deposition of impurity chloride.