The invention discloses a steel-plastic composite pipe. The steel-plastic composite pipe comprises a steel strip (4) with a specially-shaped cross section and plastic coatings (2), and is characterized in that: the specially-shaped cross section of the steel strip is hollow and closed; the steel strip is spirally wound to form a tubular body (1); adjacent edges of the steel strip are fixedly welded; and both inner layer and outer layer of the tubular body are provided with the plastic coatings. Since the specially-shaped steel strip has a hollow and closed structure and is wound and welded to form the tubular body, the ring stiffness of a pipeline is obviously improved, high-strength pressure can be born, the pipe is difficultly degummed and squeezed to be broken, and the aims of high strength, high pressure bearing capacity, firm steel-plastic adhesion, difficulty in separating steel from plastic and continuous integral steel strips are fulfilled.