The finite element analysis software Workbench was applied to simulate the temperature field under different controlled cooling process of hot rolling I-beam and the aim is to find the better controlled cooling process: from the initial cooling temperature of 900℃, firstly air-cooling 5s, then water-cooling 5s (water density is different, the R angle of strong cold at 5. 5L/(m2·s), the web at 3. 5L/(m2·s), the rest at 4. 5L/(m2·s), then the temperature field is verified using temperature measuring instrument, and the theoretical value and analog value is consistent. Mechanical properties are greatly improved, which provides the theoretical basis for the further optimization of controlled cooling process.