The invention discloses a method for measuring the current demand of area cathode protection. The method includes the steps that a temporary cathode protection system is established at the scene, the cathode protection switch-off potential of a protected structure is measured after the protected structure is fully polarized, and meanwhile the cathode protection currents output by the temporary cathode protection system are recorded; and then the cathode protection currents required by the protected structure are determined according to theoretical calculation. Compared with a traditional estimation method, the current demand of area cathode protection, measured through the method, gets closer to the actual situation, more accuracy is achieved, the reliability is higher, and the confidence level is also higher. Meanwhile, by the adoption of the method, the attenuation condition of the structure cathode protection potential in area cathode protection can be determined, the protection scope of an auxiliary anode ground bed is preset, the cathode protection currents shield the information like a serious area, and thus an important reference base is provided for optimization design of area cathode protection.