High-specific-stiffness lightweight raft frame

The high-specific-stiffness lightweight raft frame comprises a lower platform, the upper end of the lower platform is fixedly connected with a stand column through a fastener, and the upper end of the stand column is fixedly connected with an upper platform through other fasteners. According to the structure, the weight of the raft frame can be obviously reduced, meanwhile, the raft frame still has high rigidity, the manufacturing cost is low, the quality is reliable, dismounting and mounting are convenient, and the raft frame has the characteristic of high specific rigidity; the sections of all the components of the upper platform, the lower platform, the stand columns and the inclined columns have the H-shaped characteristic, an I-shaped steel structure is simulated, all welding seams are exposed, the welding difficulty is low, the welding quality is high, and flaw detection is easy; a three-dimensional triangular stable structure is formed among the stand columns, the upper platform and the lower platform,