Multi-element CSP is different with current common alumina composite pipe, in its inner wall,an additional Polymer-Matrix Composite(PMC) material is added, this material has the good performance of abrasion resistance, acid-proofing, alkali proofing, anti-fouling, hydrolysis aging proofing, etc. It greatly improves the defects of all kinds of previous old type composite steel pipes. It is widely used for industry of electric power, coal, mine, construction material ,chemistry etc. to transfer many kinds of grinding particle and erosive media, it is regarded as a super-fit composite steel pipe. Performance: 1. Outstanding wear resistance performance. Common alumina lined steel pipe's inner layer is Moo's porcelain, wear-resistant index is only 0.04. But for multi-element CSP, its index is 0.02, its performance is 2.5 times better than common alumina lined steel pipe, it is especially suit for ash removing in power station, coal powder conveyor, mine transferring and Cbackfilling pipeline, etc. 2. Anti-corrosion, anti-fouling. Multi-element CSP has good acid ,alkali and sea water erosion resistance and dirty prevention character. For example, its acid erosion resistance is 98-99%, 2 times than common alumina lined steel pipe. 3. Completely common alumina CSP defects avoiding. Although common alumina lined steel pipe has good resistance performacne for high temperature, wear and corrosion, as it is ceramic property, it is easily fallen in to pieces, easily broken at welding area, and easily caducous. For Multi-element CSP, the high polymer polymerization layer formed through the special craft which let the high polymer attaches firmly on the inner wall of alumina lined steel pipe. And with its character of fluidity, it absolutely cover the welding area. Therefoe it completely avoid the disadvantage for common alumina lined steel pipe, and its service lifetime is greatly improved.