An introduction of the corrosion problems and relevant corrosion mechanism of aluminium equipment in chemical fertilizer factories are given.Aiming at this tendency that chemical treatment can not completely con- trol the corrosion parts of the water box for carbonization, cathodic protection is introduced in detail in order to protect the aluminium equipment.Explanations are given not only on the mechanism of cathodic protection but on its implementation scheme.Based on practical experiences, the calculation of the sizes of the equipment and the protected areas, the arrangement of the cathode and anode, and the surface treatment and coating of the e- quipment are emphasized.To verify the effectiveness of this method, the application efficacy of cathodic pro- tectin is introduced especially in two aspectsintuitionistic effect and sample tests.The theory and practice prove that cathodic protection is an effective method for protecting aluminium equipment in chemical fertilizer facto- ries.