With characteristics of large bulk, great weight and great driving force, a rack is often used in the assembly and staring of the shield machine as a base platform. The conventional rack is such a base platform that it can only prevent the side rolling and displacement of the body of the shield machine. In this thesis, a rack will be introduced for rotary shield machine body, which can turn the difficult welding operation at the bottom of the shield machine to a favorable position and which also can make several people operate simultaneously. And by so doing, welding process control and working efficiency get ensured and no safety hazards exist, which have solved all the issued in conventional rack operations in a better way.