The utility model discloses a three-line-set tower crane. The three-line-set tower crane comprises an under frame, wherein a left tail bracket and a right tail bracket are hinged to the rear end of the under frame; a left rope winder and a right rope winder are respectively mounted on the left tail bracket and the right tail bracket; a power plant is arranged at the rear part of the under frame; a winch is arranged in the middle of the under frame; double-roller devices are arranged on the left side and the right side in the front of the under frame; the structures of the double-roller devices are identical and both comprise double-roller main beams and double-roller secondary beams which are respectively mounted on the under frame left and right at intervals; four rollers are arranged between the double-roller main beams and the double-roller secondary beams side by side at intervals front and back; at least one of the rollers is driven by a hydraulic motor reduction gear; a towing bar is forwards connected with the front end of the under frame; travelling wheels are respectively downwards arranged on the left side and the right side of the middle part of the under frame. The three-line-set tower crane disclosed by the utility model can be used for hoisting the tower material and lifting and adjusting a derrick body, realizes centralized control of all power for hoisting the tower material, reduces information communication among the hoisting operating personnel, and is convenient to operate; meanwhile the three-line-set tower crane is stable in hoisting operation, high in impact resistance, good in safety, and convenient to transfer.