Abstract: Due to the narrow deformation temperature range of titanium alloy in the process of equal channel extrusion forming, it is often necessary to preheat the die at a higher temperature so as to reduce the influence of the billet temperature drop on the deformation process. In order to reduce the influence of mold temperature on the forming process and the deformation of the mold by thermal expansion, the method of zonal preheating of the mold was proposed, and a three-factor four-level orthogonal experiment was designed, and 16 groups of orthogonal schemes were analyzed using polar analysis to optimize the zonal preheating scheme of the mold.The influences of the 380 ℃ preheating and zone preheating(deformation zone 380 ℃ +other zones 150 ℃) of the mold on forming load, billet stress and strain, thermal expansion of the mold, billet forming effect and microstructure were compared and analyzed. The results show that the equivalent strain of the material decreases from 2.76 to 2.44 after zonal preheating of the die, the equivalent stress decreases from 379 MPa to 352 MPa; the temperature of the billet after extrusion is 316 ℃, which decreases by 38 ℃. The forming load decreases by 2.9 kN, and the maximum is 24.6 kN; the maximum expansion of the mold decreases by 0.30 mm compared with that of the overall preheating, and the expansion of the deformation zone decreases by 0.15 mm. The forming effect after zonal heating is more superior, and the grain size refinement is more obvious, which is about 5 μm.