Abstract: When Ti slab smelting by electron beam cold hearth melting furnace is finished, the high temperature will bring the Ti slab bending deflection length direction. To avoid the deformation, the vacuum cooling time shall last 8 hours, and the maximum temperature is about 100℃. PROCAST FEM software and proved by practice practical production prove the maximum temperature of slab is about 200℃ after cooling 3 hours. when the temperature decreases from 200℃ to 100℃, the vacuum cooling rate is 22. 5℃/h, and the air cooling rate is 25. 7℃/h. The cooling rates in both conditions are almost same. As a conclusion, 3 hours of cooling time has a minimal influence on the deformation, while the production efficiency has been improved obviously.