Abstract: The research of large diameter and thick wall pipe bending process of CAP1400 SGS system was carried out.Medium frequency induction local heating was used during bending, and induction coil width of bending equipment was adjusted, appropriate compensation angle was set, and appropriate propulsion speed and medium frequency induction power were selected.After the bending was completed, normalizing and tempering heat treatment were carried out.The normalizing process was 920℃×190 min, water cooling; the tempering process was 670℃×150 min, furnace cooling. After the bending was completed, the appearance quality, bending radius, wall thickness reduction rate, and ovality of the elbow were inspected, and corresponding non-destructive inspections (including penetration inspection and ultrasonic inspection), physical and chemical tests(including room temperature tensile test, high temperature tensile test, impact test, grain size test) and hydraulic test were conducted. After the above inspection, the intermediate frequency induction heating bending pipe meets the corresponding standard requirements.