The invention discloses a gantry measuring device double-cross beam design structure adopting combination of a guide beam and a bearing driving beam. The gantry measuring device double-cross beam design structure comprises the guide beam, an air cushion, an YZ shaft guiding ramp, a Z shaft speed reducer, a Z shaft, the bearing driving beam, a driving guide rail, a driving base, a counterweight mechanism, a Y shaft speed reducer, an X shaft slider connecting plate, and a steel wire rope. The two ends of the guide beam and the two ends of the bearing driving beam are parallely installed and connected by the X shaft slider connecting plate, and the driving guide rail is disposed on the bearing driving beam. The YZ shaft guiding ramp is disposed on the guide beam by the air cushion, and is connected with the Z shaft, and the Y shaft speed reducer and the counterweight mechanism are disposed on the driving base. The driving base is connected with the driving guide rail, and when the driving base moves along the driving guide rail, the YZ shaft guiding ramp and the Z shaft are driven to slide along the guide beam, and in addition, the Z shaft and the YZ shaft guiding ramp are connected with the counterweight mechanism by the steel wire rope, and the bearing driving beam is used to bear the weight of the Z shaft and the weight of the YZ shaft guiding ramp, and therefore the Y, Z shaft guiding and the bearing driving of the gantry measuring device are completed by two independent cross beams.