The invention discloses a steel truss girder erecting system and method and a lifting station. The lifting station comprises hoisting equipment and a slideable girder; the hoisting equipment is arranged on an upper chord of the erected steel truss girder; a bridge deck is paved on a lower chord of the steel truss girder; the part of the bridge deck opposite to the hoisting equipment is provided with a notch for conveying a steel truss girder rod member; the transversely-arranged sliding plates are paved on the bridge decks on the two sides of the notch respectively; and the two ends of the slideable girder are placed on the sliding plates respectively. When a steel truss girder is erected, the slideable girder is transversely moved firstly to enable the steel truss girder rod member to penetrate through the notch and is lifted to the space above a girder conveying trolley; and then, the slideable girder is transversely moved to be butted with the left and right lower longitudinal sliding tracks, and the steel truss girder rod member is placed on the girder conveying trolley and longitudinally transported to the erecting position through the girder conveying trolley. In the invention, a cantilever cradle is not adopted, small space is occupied, a small amount of steel is used, influence on the construction of the major structure is little, and the construction is convenient.