The invention relates to a fixing device for transverse profiled plates and an installation method thereof. Each fixing frame of the device includes a vertical bar and a transverse pipe arranged on one side of the vertical bar. A first fixing frame and a second fixing frame are placed opposite to each other. The transverse pipes are located inside. The diameter of the transverse pipe of the firstfixing frame is larger than the diameter of the transverse pipe of the second fixing frame. The transverse pipe of the first fixing frame sleeves the transverse pipe of the second fixing frame. The two transverse pipes are provided with long circular holes and are fixed by adjusting bolts. A number of supporting parts are arranged at intervals outside the vertical bars of the first fixing frame and the second fixing frame, and each supporting part is provided with a reserved hole. The problem that transverse metal profiled plates need to be installed separately at high altitude is solved. Theinstallation quality and efficiency of transverse profiled plates are greatly improved.