▎ 摘　　要

NOVELTY - Preparing auxiliary anode comprises (i) preparing a coating solution A containing carboxylated graphene, an iridium compound and a tantalum compound, and preparing a coating solution B containing carboxylated graphene, and (ii) coating the coating solution A on the surface of the metal substrate to form the coating layer A, then coating the coating solution B on the surface of the coating layer A to form the coating layer B, and sintering in a protective atmosphere. USE - Preparation method of auxiliary anode used in cathode protection system in floating production oil storage and oil discharging device and sea water pipeline on platform. The auxiliary anode is used in external current cathode protection system. ADVANTAGE - The method provides an auxiliary anode with more excellent performance and longer service life. The method is simple, low cost, controllable load amount, suitable for popularization and practical application. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an auxiliary anode.