In order to solve the problem of replacement of common anodes used in settling tanks, a replaceable sacrificial anode for corrosion protection of the inner wall of crude oil settling tanks was designed and developed. The replaceable sacrificial anode consists of a replaceable unit, a welded iron foot, a corrosion-proof buckle box, etc.The material of sacrificial anode is an aluminum-zinc-indium alloy.The protection is applied to 4m below inner wall of the 2000m3settlement tank and the tank bottom floor, with the design life of 8 to 10 years, the minimum protection potential: -0.85V, a total of 62 anodes.When used for the first time, it needs to be installed by weldingand it can be replaced by removing the bolts withoutelectricity and fire, which can effectively reduce the work intensity and safety hazards caused by the conventional sacrificial anode replacement work.The research has certain reference significance for the replacement of sacrificial anodes in pipelines and ships.