The invention provides a splicing backplane for a backlight module, which is arranged on the backside of the backlight module. The splicing backplane comprises a mounting portion and a supporting portion, wherein the horizontal height of the mounting portion is level with or lower than that of the supporting portion; and a plurality of the splicing backplanes are assembled together by the mutual superposition of various mounting portions. A plurality of the splicing backplanes are superposed with each other and combined into one, and the height differences between the mounting portions and the supporting portions of two adjacent backplanes are unequal, so that one backplane can be accommodated into the other backplane. In addition, after the superposition, the overall thickness of the backplanes is invariable.