Abstract: Central manifold is one of the most complex and typical core equipment in deep water production system. Excellent pipeline corrosion protection is the key to ensure the maintenance free of the equipment in its service life. Combined with engineering application, the function of corrosion protection coating of duplex stainless steel pipeline under cathodic protection is explained, and the process and detection means of corrosion protection coating are introduced from the aspects of surface treatment, coating system and coating repair.