This project studied on technique of induction cladding alloy layer in steel tube outer wall and property of alloy layer, briefly introduced the principle of technique, technique assemble and outstanding character, and analyzed the microstructure of prepared cladding layer. Result showed that there existed a clear bright transition band between cladding layer and body, and the metallurgical bonding performed very well. The alloy cladding layer microstructure present as form of eutectic between austenite + carbide (some austenite dendritic crystal can be seen in some zone), this technique is applied for steel tube outer wall strengthening. Compared to the current technique, it could protect environment and had advantage of high combining strengthen, speed and low cost and with no interstice and slag inclusion.