Abstract: Reviewed here in the artic le are the manufacturing process， the bounding interface and the thread connection design of the metallurgical composite oil casing. The characteristics of the metallurgical bounding interface is discussed. As a result it is revealed that the currently-used manufacturing process for the said oil casing leads to occurrence of the gradients of the casing’s chemical composition，microstructure and properties. And the safety of the currently-disclosed thread design of the metallurgical composite oil casing is not verified via in-well service. The research fields of the said composite oil casing is prospected，i.e.，accurately gradient control and measurement，new heat treatment as balancing the properties of both the outer layer and the inner layer，and the thread connection design as based on self galvanic corrosion.