Trussed gantry crane

The utility model discloses a trussed gantry crane, comprising a portal main frame structure which is composed of left and right landing legs and a girder, wherein left and right track walking mechanisms are respectively arranged at the lower ends of the left and right landing legs; the girder is a trussed single girder; two walking guide rails are arranged on the girder in parallel along the longitudinal direction; a walking crown block driven by a power source is arranged on each walking guide rail; left and right hoisting mechanisms are symmetrically arranged on the walking crown blocks; balance suspension girders with hangers are suspended below the left and right hoisting mechanisms through wire ropes; and an electric hoist lifting device is suspended below the girder. The trussed gantry crane has the advantages that a single-girder and dual-track structure is adopted, the dead load is relatively light, and the manufacturing cost is greatly reduced; independent double hoisting mechanisms are adopted on the walking crown blocks, and hoisting is stable by using a dual-hanging point mechanism, so that the work efficiency is improved; and meanwhile, the electric hoist lifting device playing an auxiliary role is arranged below the girder, so that the hoisting and operating processes are more stable and ordered.