Horizontal supporting device of building external frame

The utility model discloses a horizontal supporting device of a building external frame, which comprises a supporting body, and is characterized in that the supporting body consists of a support connecting plate, front supporting arms, rear supporting arms and hanging rings, wherein the support connecting plate is provided with mounting holes, one end of each front supporting arm is connected with the support connecting plate while the other end is connected with each rear supporting arm, the hanging rings are arranged on two sides of the rear supporting arms, and an elongated arm is arranged between each front supporting arm and each rear supporting arm. Therefore, the length of the horizontal supporting device can be optionally combined, different lengths can be combined to meet installation requirement, and then the horizontal supporting device can be adaptable to thicknesses of different building walls and guarantee that an external frame is fixedly connected to the building wall without hindering construction operation. In addition, the horizontal supporting device saves material, reduces cost and has convenient process and easy mounting and dismounting.